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Braï MA, Hannachi N, El Gueddari N, Baudoin JP, Dahmani A, Lepidi H, Habib G, Camoin-Jau L. The Role of Platelets in Infective Endocarditis. Int J Mol Sci 2023; 24:ijms24087540. [PMID: 37108707 PMCID: PMC10143005 DOI: 10.3390/ijms24087540] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/02/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation. In this review, we will analyze the key role of platelets in the physiopathology of endocarditis and in the formation of vegetation, depending on the bacterial species. We provide a comprehensive outline of the involvement of platelets in the host immune response, investigate the latest developments in platelet therapy, and discuss prospective research avenues for solving the mechanistic enigma of bacteria-platelet interaction for preventive and curative medicine.
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Affiliation(s)
- Mustapha Abdeljalil Braï
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- IHU Méditerranée Infection, Boulevard Jean Moulin, 13385 Marseille, France
| | - Nadji Hannachi
- Laboratoire de Biopharmacie et Pharmacotechnie, Faculté de Médecine, Université Ferhat Abbas Sétif I, Sétif 19000, Algeria
| | - Nabila El Gueddari
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Service de Chirurgie Cardiaque, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, 13385 Marseille, France
| | - Jean-Pierre Baudoin
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- IHU Méditerranée Infection, Boulevard Jean Moulin, 13385 Marseille, France
| | - Abderrhamane Dahmani
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- IHU Méditerranée Infection, Boulevard Jean Moulin, 13385 Marseille, France
| | - Hubert Lepidi
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Service d'Anatomo-Pathologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, 13385 Marseille, France
| | - Gilbert Habib
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Service de Cardiologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, 13385 Marseille, France
| | - Laurence Camoin-Jau
- IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix Marseille University, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
- Laboratoire d'Hématologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, 13385 Marseille, France
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Hannachi N, Ogé-Ganaye E, Baudoin JP, Fontanini A, Bernot D, Habib G, Camoin-Jau L. Antiplatelet Agents Have a Distinct Efficacy on Platelet Aggregation Induced by Infectious Bacteria. Front Pharmacol 2020; 11:863. [PMID: 32581813 PMCID: PMC7291881 DOI: 10.3389/fphar.2020.00863] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 05/26/2020] [Indexed: 02/01/2023] Open
Abstract
Platelets are the cornerstone of hemostasis. However, their exaggerated aggregation induces deleterious consequences. In several diseases, such as infectious endocarditis and sepsis, the interaction between platelets and bacteria leads to platelet aggregation. Despite platelet involvement, no antiplatelet therapy is currently recommended in these infectious diseases. We aimed here, to evaluate, in vitro, the effect of antiplatelet drugs on platelet aggregation induced by two of the bacterial pathogens most involved in infectious endocarditis, Staphylococcus aureus and Streptococcus sanguinis. Blood samples were collected from healthy donors (n = 43). Treated platelet rich plasmas were incubated with three bacterial strains of each species tested. Platelet aggregation was evaluated by Light Transmission Aggregometry. CD62P surface exposure was evaluated by flow cytometry. Aggregate organizations were analyzed by scanning electron microscopy. All the strains tested induced a strong platelet aggregation. Antiplatelet drugs showed distinct effects depending on the bacterial species involved with different magnitude between strains of the same species. Ticagrelor exhibited the highest inhibitory effect on platelet activation (p <0.001) and aggregation (p <0.01) induced by S. aureus. In the case of S. sanguinis, platelet activation and aggregation were better inhibited using the combination of both aspirin and ticagrelor (p <0.05 and p <0.001 respectively). Aggregates ultrastructure and effect of antiplatelet drugs observed by scanning electron microscopy depended on the species involved. Our results highlighted that the effect of antiplatelet drugs depended on the bacterial species involved. We might recommend therefore to consider the germ involved before introduction of an optimal antiplatelet therapy.
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Affiliation(s)
- Nadji Hannachi
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
| | - Emma Ogé-Ganaye
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
- Laboratoire d’Hématologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, Marseille, France
| | - Jean-Pierre Baudoin
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
| | - Anthony Fontanini
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
| | - Denis Bernot
- Laboratoire d’Hématologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, Marseille, France
| | - Gilbert Habib
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
- Département de cardiologie, Hôpital de la Timone, AP-HM, Boulevard Jean-Moulin, Marseille, France
| | - Laurence Camoin-Jau
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée infection, Marseille, France
- Laboratoire d’Hématologie, Hôpital de la Timone, APHM, Boulevard Jean-Moulin, Marseille, France
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Hannachi N, Baudoin JP, Prasanth A, Habib G, Camoin-Jau L. The distinct effects of aspirin on platelet aggregation induced by infectious bacteria. Platelets 2019; 31:1028-1038. [PMID: 31856631 DOI: 10.1080/09537104.2019.1704717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacteria induce platelet aggregation triggered by several mechanisms. The goal of this work was to characterize platelet aggregates induced by different bacterial strains and to quantify the effect of aspirin treatment using aggregation tests, as well as a novel approach based on confocal analysis. Blood samples were obtained from either healthy donors (n = 27) or patients treated with long-term aspirin (n = 15). The bacterial species included were Staphylococcus aureus, Enterococcus faecalis, and Streptococcus sanguinis. The different aggregate's ultrastructures depending on the bacterial strain were analyzed using Scanning electron microscopy. Quantification of the size of the platelet aggregates, their mean number as well as the bacterial impregnation within the aggregates was performed using confocal laser scanning light microscopy. Light Transmission Aggregometry was also performed. Our results reported distinct characteristics of platelet aggregates depending on the bacterial strain. Using confocal analysis, we have shown that aspirin significantly reduced platelet aggregation induced by S. aureus (p = .003) and E. faecalis (p = .006) with no effect in the case of S. sanguinis (p = .529). The results of the aggregometry were concordant with those of the confocal technique in the case of S. aureus and S. sanguinis. Interestingly, aggregation induced by E. faecalis was detected only with confocal analysis. In conclusion, our confocal scanning microscopy allowed a detailed study of the platelet aggregation induced by bacteria. We showed that aspirin acts on bacterial-induced platelet aggregation depending on the species. These results are in favor of the use of aspirin considering the species and the bacterial strain involved.
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Affiliation(s)
- Nadji Hannachi
- Département d'infectiologie, MEPHI, IHU Méditerranée infection, Aix Marseille Univ, IRD, AP-HM , Marseille, France
| | - Jean-Pierre Baudoin
- Département d'infectiologie, MEPHI, IHU Méditerranée infection, Aix Marseille Univ, IRD, AP-HM , Marseille, France
| | - Arsha Prasanth
- Département d'infectiologie, MEPHI, IHU Méditerranée infection, Aix Marseille Univ, IRD, AP-HM , Marseille, France
| | - Gilbert Habib
- Département d'infectiologie, MEPHI, IHU Méditerranée infection, Aix Marseille Univ, IRD, AP-HM , Marseille, France.,Département de cardiologie, la Timone Hospital, AP-HM , Marseille, France
| | - Laurence Camoin-Jau
- Département d'infectiologie, MEPHI, IHU Méditerranée infection, Aix Marseille Univ, IRD, AP-HM , Marseille, France.,Laboratoire d'Hématologie, La Timone Hospital, APHM , Marseille, France
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4
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The Role of Platelets in Antimicrobial Host Defense. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00029-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Nurden AT. Should studies on Glanzmann thrombasthenia not be telling us more about cardiovascular disease and other major illnesses? Blood Rev 2017; 31:287-299. [PMID: 28395882 DOI: 10.1016/j.blre.2017.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/23/2017] [Indexed: 12/17/2022]
Abstract
Glanzmann thrombasthenia (GT) is a rare inherited bleeding disorder caused by loss of αIIbβ3 integrin function in platelets. Most genetic variants of β3 also affect the widely expressed αvβ3 integrin. With brief mention of mouse models, I now look at the consequences of disease-causing ITGA2B and ITGB3 mutations on the non-hemostatic functions of platelets and other cells. Reports of arterial thrombosis in GT patients are rare, but other aspects of cardiovascular disease do occur including deep vein thrombosis and congenital heart defects. Thrombophilic and other risk factors for thrombosis and lessons from heterozygotes and variant forms of GT are discussed. Assessed for GT patients are reports of leukemia and cancer, loss of fertility, bone pathology, inflammation and wound repair, infections, kidney disease, autism and respiratory disease. This survey shows an urgent need for a concerted international effort to better determine how loss of αIIbβ3 and αvβ3 influences health and disease.
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Affiliation(s)
- Alan T Nurden
- Institut de Rhythmologie et de Modélisation Cardiaque, Plateforme Technologique d'Innovation Biomédicale, Hôpital Xavier Arnozan, Pessac, France.
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6
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Periodontitis, Bacteremia and Infective Endocarditis: A Review Study. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2017. [DOI: 10.5812/pedinfect.41067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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7
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Abstract
Multiple studies have now shown that various species of bacteria can stimulate platelets; many in a strain and donor-dependent manner. The signalling pathways underlying this platelet activation has been the subject of scrutiny for the last decade. The best-delineated pathway is that in response to Streptococcal species, such as Streptococcus sanguinis (S. sanguinis), Streptococcus gordonii (S. gordonii) and Streptococcus oralis (S. oralis), where a pathway is initiated by the engagement of the low affinity IgG receptor, FcγRIIA. This leads to and involves the tyrosine kinase Syk, the adaptor protein Linker of Activated T Cells (LAT) and subsequently both phospholipase Cγ2 (PLCγ2) and phosphatidylinositol-3-kinase (PI-3-K). Finally, this leads to the expression of the αIIbβ3 integrin, the synthesis and release of thromboxane A2 (T × A2) and the exocytosis of PF4, each of which plays a crucial role in secondary signalling and full platelet activation. Roles for other signalling pathways in Streptococcal-induced platelet activation are less clear, although an ADP-mediated inhibition of adenylyl cyclase, a glycoprotein Ib/IX/V-mediated pathway and perhaps a complement-induced pathway have each been proposed. Platelet activation by Porphyromonas gingivalis (P. gingivalis) at least partially shares the FcγRIIA/Syk/PLCγ2/PI-3-K mechanism utilised by Streptococcal species. However, it has also been suggested that P. gingivalis activates platelets by two additional methods; stimulation of the protease-activated receptors leading to activation of phospholipase Cβ (PLCβ), and the engagement of Toll-like receptors 2 and 4 by released lipopolysaccharide leading to an ill-defined pathway which may involve PI-3-K. Consequently, it appears that bacteria can stimulate platelets by eliciting multiple signalling pathways some of which are common, and some unique, to individual species.
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Abstract
Given their small size, platelets are emerging as being one of the most important entities in the bloodstream. Not only do they play a key role in maintaining thrombosis and haemostasis, platelets also play a critical role in orchestrating the immune response. Being the first cell at the site of injury, they are perfectly placed to assess the extent of the damage and recruit immune cells as is necessary. As a first line of defence, platelets can act as primitive immune cells themselves by interacting with invading pathogens. A number of platelet receptors have been shown to interact with bacteria either directly or indirectly, involving a plasma protein bridge. This review will discuss the molecular mechanisms that exist between platelets and bacteria and the functional response to the interaction. We will also discuss the importance of considering animal models of disease and the use of physiological shear when studying platelet-bacterial interactions.
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Affiliation(s)
- Steven W Kerrigan
- School of Pharmacy & Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland , Dublin , Ireland
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Singh P, Khullar S, Singh M, Kaur G, Mastana S. Diabetes to cardiovascular disease: is depression the potential missing link? Med Hypotheses 2015; 84:370-8. [PMID: 25655224 DOI: 10.1016/j.mehy.2015.01.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 12/12/2014] [Accepted: 01/21/2015] [Indexed: 01/15/2023]
Abstract
The etiopathological consequences of diabetes and its imperative sequels have been explored extensively in the scientific arena of cardiovascular diabetology. Innumerable risk covariates and confounders have been delineated for the primary and secondary prevention of diabetes and cardiovascular diseases (CVD). However, an intricate interaction of depression on them has been largely overlooked. Depression influences and participates in each and every step that worsens the diabetic state for developing cardiovascular complications. The dilemma is that it coexists, remains silent and generally not considered as relevant clinical parameter amenable to intervention. In this review, it is highlighted that depression has strong association and linkages with both diabetes and CVD and it should be considered and diagnosed at every stage of the diabetes to CVD continuum. Careful attention to the diagnosis and management of these disease states would contribute in lessening the CVD burden of the society.
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Affiliation(s)
- Puneetpal Singh
- Department of Human Genetics, Punjabi University, Patiala, India
| | - Shallu Khullar
- Department of Human Genetics, Punjabi University, Patiala, India
| | - Monica Singh
- Department of Human Genetics, Punjabi University, Patiala, India
| | - Gurpreet Kaur
- Department of Human Genetics, Punjabi University, Patiala, India
| | - Sarabjit Mastana
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
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10
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Abdulrehman AY, Jackson ECG, McNicol A. Platelet activation by Streptococcus sanguinis is accompanied by MAP kinase phosphorylation. Platelets 2012; 24:6-14. [PMID: 22372533 DOI: 10.3109/09537104.2012.661105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
There is increasing interest in the role of infections in atherothrombotic conditions. In particular, bacteria, notably those of oral origin, have been shown to activate platelets using a variety of mechanisms. Previous studies have shown that S. sanguinis strain 2017-78 induces platelet aggregation which requires the presence of both vWF and IgG. This aggregation is accompanied by the consecutive phosphorylation/desphosphorylation/rephosphorylation of several signalling proteins. The first two phases are thromboxane-dependent whereas the rephosphorylation phase is mediated by engagement of the αIIbβ3 integrin. Here signalling events, specifically the potential role of MAP kinases, associated with S. sanguinis strain 2017-78-induced platelet activation have been further examined using an immunoblotting approach. The addition of S. sanguinis strain 2017-78 caused a similar triphasic phosphorylation profile of the platelet MAP kinase Erk2 to that seen with other phosphoproteins. Pretreatment with aspirin or RGDS did not affect 2017-78-induced Erk2 phosphorylation or desphosphorylation but both inhibited the rephosphorylation phase. In contrast the level of 2017-78-induced platelet MAP kinase p38 phosphorylation remained at an elevated level, and this was unaffected by aspirin. Similarly, 2017-78-induced cPLA(2) phosphorylation remained above basal levels during the aggregation process. The p38 inhibitor SB203580 inhibited S. sanguinis-induced aggregation with no effect on the phosphorylation of either p38 or cPLA(2). Thus the current study demonstrates the activation of both the Erk2 and p38 forms of MAP kinases, and of cPLA(2), in platelets stimulated with S. sanguinis strain 2017-78, and is consistent with a role for Erk2, but not for p38, in the cPLA(2) phosphorylation in response to S. sanguinis.
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Affiliation(s)
- Ahmed Y Abdulrehman
- Departments of Oral Biology, University of Manitoba, Winnipeg, Manitoba, Canada
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11
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Vanassche T, Peetermans WE, Herregods MC, Herijgers P, Verhamme P. Anti-thrombotic therapy in infective endocarditis. Expert Rev Cardiovasc Ther 2012; 9:1203-19. [PMID: 21932963 DOI: 10.1586/erc.11.100] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Despite advances in medical and surgical treatment, infective endocarditis (IE) still carries a high risk of morbidity and mortality. One of the determinants of an adverse outcome is the presence of systemic embolization and in particular, of CNS embolization. IE vegetations consist of bacteria, platelets and inflammatory cells in a fibrin mesh. The interactions between pathogens, platelets and the coagulation system are critical to vegetation initiation and growth. This understanding has led to the study of the effect of anti-thrombotic treatment on IE vegetation formation and embolization. Although it has been demonstrated that antiplatelet and anticoagulant strategies have an impact on in vitro and animal models of IE, results from the available clinical studies are conflicting. In this article, we provide an overview of the available experimental and clinical data on anti-thrombotic treatment in IE and summarize the current guidelines. An early diagnosis, prompt empiric antibiotic treatment and a careful selection of patients who benefit from early surgical intervention remain essential in the prevention of embolic complications. In patients who have other indications for antiplatelet or anticoagulant treatment, the continuation of this treatment is deemed safe in the absence of hemorrhagic complications.
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Affiliation(s)
- Thomas Vanassche
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.
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12
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Yeaman MR. Bacterial-platelet interactions: virulence meets host defense. Future Microbiol 2010; 5:471-506. [PMID: 20210555 DOI: 10.2217/fmb.09.112] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Platelets have historically been viewed as cell fragments that only mediate blood coagulation. Yet, platelets have as - or perhaps even more - important roles in tissue remodeling, modulation of inflammation and antimicrobial host defense. It is evident that platelets interact with prokaryotes directly and indirectly through multiple molecular and cellular mechanisms. The important roles of platelets in antibacterial host defense can be exemplified through contemporary themes in platelet immunobiology. Platelets have unambiguous structures and functions of host defense effector cells. Recent discoveries reveal platelet expression of toll-like and purinonergic receptors, which enable detection and response to bacterial infection, degranulation of an array of microbicidal peptides and coordination of other molecular and cellular host defenses. From multiple perspectives, platelets are now increasingly recognized as critical innate immune effector cells that also bridge and facilitate optimization of adaptive immunity. It follows that clinical deficiencies in platelet quantity or quality are now recognized correlates of increased risk and severity of bacterial and other infections. Along these lines, new evidence suggests that certain prokaryotic organisms may be capable of exploiting platelet interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved highly coordinated means by which to seize opportunities to bind to surfaces of activated platelets, and exploit them to establish or propagate infection. Hence, it is conceivable that certain bacterial pathogens subvert platelet functions. From these perspectives, the net consequences of bacterial virulence versus platelet host defenses likely decide initial steps towards the ultimate result of infection versus immunity.
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Affiliation(s)
- Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at UCLA, Harbor-UCLA Medical Center, 1124 West Carson Street, RB-2, Torrance, CA 90502, USA.
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13
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McNicol A, Israels SJ. Mechanisms of oral bacteria-induced platelet activation. Can J Physiol Pharmacol 2010; 88:510-24. [DOI: 10.1139/y10-029] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The oral cavity is inhabited by over 500 different bacterial species that normally exist in ecological balance both with each other and with the host. When this equilibrium is disturbed, an overgrowth of individual organisms can occur, which, in turn, can lead to the onset of pathological processes, notably dental caries and periodontitis. Generally, bacteraemias occur more frequently in individuals with periodontal disease, and these bacteraemias have been implicated in the development of a range of systemic diseases, including atherothrombotic disorders. The mechanism underlying this relationship remains to be precisely defined, although studies have shown a link between bacteria of oral origin and platelet activation. Several orally derived species of bacteria interact with platelets, including those of the Streptococcus ( Streptococcus sanguinis , Streptococcus mutans , Streptococcus agalactiae , Streptococcus pyogenes , Streptococcus gordonii , Streptococcus pneumoniae , Streptococcus mitis ) and Staphylococcus ( Staphylococcus epidermidis , Staphylococcus capitis ) genera, as well as Pseudomonas aeruginosa and Porphyromonas gingivalis . In addition, some members of both the Streptococcus and the Staphylococcus genera, as well as Porphyromonas gingivalis , can activate platelets in vitro. The current review describes the heterogeneous mechanisms of platelet activation employed by individual bacterial species. The pathological and clinical implications of platelet activation by orally derived bacteria are discussed.
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Affiliation(s)
- Archibald McNicol
- Department of Oral Biology, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- International Centre for Oral Systemic Health, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
| | - Sara J. Israels
- Department of Oral Biology, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- International Centre for Oral Systemic Health, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
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14
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Abstract
Platelets interact with bacterial pathogens through a wide array of cellular and molecular mechanisms. The consequences of this interaction may significantly influence the balance between infection and immunity. On the one hand, recent data indicate that certain bacteria may be capable of exploiting these interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved specific ways in which to subvert activated platelets. Hence, it is conceivable that some bacterial pathogens exploit platelet responses. On the other hand, platelets are now known to possess unambiguous structures and functions of host defense effector cells. Recent discoveries emphasize critical features enabling such functions, including expression of toll-like receptors that detect hallmark signals of bacterial infection, an array of microbicidal peptides, as well as other host defense molecules and functions. These concepts are consistent with increased risk and severity of bacterial infection as correlates of clinical abnormalities in platelet quantity and quality. In these respects, the molecular and cellular roles of platelets in host defense against bacterial pathogens are explored with attention on advances in platelet immunobiology.
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Affiliation(s)
- Michael R Yeaman
- Division of Infectious Diseases, St. John's Cardiovascular Research Center, Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Torrance, CA 90502, USA.
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15
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Westling K, Julander I, Ljungman P, Vondracek M, Wretlind B, Jalal S. Identification of species of viridans group streptococci in clinical blood culture isolates by sequence analysis of the RNase P RNA gene, rnpB. J Infect 2008; 56:204-10. [PMID: 18255158 DOI: 10.1016/j.jinf.2007.12.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 11/18/2007] [Accepted: 12/05/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Viridans group streptococci (VGS) cause severe diseases such as infective endocarditis and septicaemia. Genetically, VGS species are very close to each other and it is difficult to identify them to species level with conventional methods. The aims of the present study were to use sequence analysis of the RNase P RNA gene (rnpB) to identify VGS species in clinical blood culture isolates, and to compare the results with the API 20 Strep system that is based on phenotypical characteristics. METHODS Strains from patients with septicaemia or endocarditis were analysed with PCR amplification and sequence analysis of the rnpB gene. Clinical data were registered as well. RESULTS One hundred and thirty two VGS clinical blood culture isolates from patients with septicaemia (n=95) or infective endocarditis (n=36) were analysed; all but one were identified by rnpB. Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii strains were most common in the patients with infective endocarditis. In the isolates from patients with haematological diseases, Streptococcus mitis and S. oralis dominated. In addition in 76 of the isolates it was possible to compare the results from rnpB analysis and the API 20 Strep system. In 39/76 (51%) of the isolates the results were concordant to species level; in 55 isolates there were no results from API 20 Strep. CONCLUSION Sequence analysis of the RNase P RNA gene (rnpB) showed that almost all isolates could be identified. This could be of importance for evaluation of the portal of entry in patients with septicaemia or infective endocarditis.
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Affiliation(s)
- Katarina Westling
- Department of Medicine, Division of Infectious Diseases, I 73, Karolinska Institutet, Karolinska University Hospital/Huddinge, SE 141 86 Stockholm, Sweden.
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16
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Antimicrobial Host Defense. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50802-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Abstract
In recent years, the frequency of serious cardiovascular infections such as endocarditis has increased, particularly in association with nosocomially acquired antibiotic-resistant pathogens. Growing evidence suggests a crucial role for the interaction of bacteria with human platelets in the pathogenesis of cardiovascular infections. Here, we review the nature of the interactions between platelets and bacteria, and the role of these interactions in the pathogenesis of endocarditis and other cardiovascular diseases.
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Affiliation(s)
- J Ross Fitzgerald
- Centre for Infectious Diseases, The Chancellor's Building, New Royal Infirmary, University of Edinburgh, Edinburgh EH16 4SB, Scotland, UK
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Plummer C, Wu H, Kerrigan SW, Meade G, Cox D, Ian Douglas CW. A serine-rich glycoprotein of Streptococcus sanguis mediates adhesion to platelets via GPIb. Br J Haematol 2005; 129:101-9. [PMID: 15801962 DOI: 10.1111/j.1365-2141.2005.05421.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Streptococcus sanguis is the most common oral bacterium causing infective endocarditis and its ability to adhere to platelets, leading to their activation and aggregation, is thought to be an important virulent factor. Previous work has shown that S. sanguis can bind directly to platelet glycoprotein (GP) Ib but the nature of the adhesin was unknown. Here, we have shown that a high molecular weight glycoprotein of S. sanguis mediates adhesion to glycocalacin. The bacterial glycoprotein was purified from cell extracts by chromatography on GPIb- and wheatgerm agglutinin affinity matrices and its interaction with GPIb was shown to be sialic acid-dependent. We designated the glycoprotein serine-rich protein A (SrpA). An insertional inactivation mutant lacking the SrpA of S. sanguis showed significantly reduced binding to glycocalacin, reduced adherence to platelets and a prolonged lag time to platelet aggregation. In addition, under flow conditions, platelets rolled and subsequently adhered on films of wild-type S. sanguis cells at low shear (50/s) but did not bind to films of the SrpA mutant. Platelets did not bind to wild-type bacterial cells at high shear (1500/s). These findings help to understand the mechanisms by which the organism might colonize platelet-fibrin vegetations.
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Affiliation(s)
- Christopher Plummer
- Department of Oral Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
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19
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Abstract
Oral bacteria inhabit biofilms, which are firm clusters adhering in layers to surfaces and are not easily eliminated by immune responses and are resistant to antimicrobial agents. Dental plaque is one such biofilm. In the past 10 years, subgingival plaque bacteria forming biofilms have been increasingly reported to be involved in systemic diseases. A close relationship between microbial infections and vascular disease has also been reported in the past two decades. The present review discusses the significance of the ecologic characteristics of biofilms formed by periodontopathic bacteria in order to further clarify the associations between periodontal disease and systemic disease. We focus on the relationships between periodontal disease-associated bacteria forming biofilms and vascular diseases including atherosclerosis and carotid coronary stenotic artery disease, and we discuss the direct and indirect effects on vascular diseases of lipopolysaccharides as well as heat shock proteins produced by periodontopathic bacteria.
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Affiliation(s)
- K Okuda
- Department of Microbiology, Oral Health Science Center, Tokyo Dental College, Mihama-ku, Chiba, Japan.
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20
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Brouwers FM, Oyen WJG, Boerman OC, Barrett JA, Verheugt FWA, Corstens FHM, Van der Meer JWM. Evaluation of Tc-99m-labeled glycoprotein IIb/IIIa receptor antagonist DMP444 SPECT in patients with infective endocarditis. Clin Nucl Med 2003; 28:480-4. [PMID: 12911097 DOI: 10.1097/01.rlu.0000067508.82824.75] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Infective endocarditis (IE) is characterized by aggregation of activated platelets, fibrin, and bacteria. DMP444, a high-affinity glycoprotein IIb/IIIa receptor antagonist, binds to the fibrinogen-binding domain of activated platelets, depicting a key feature of IE. Tc-99m DMP444 scintigraphy was studied in a group of patients with possible IE. METHODS Tc-99m DMP444 (600 MBq; 16 mCi) planar and SPECT images of the heart were recorded in patients with possible IE for as long as 6 hours after injection. Results were compared to echocardiography and the Duke classification. RESULTS Sixteen patients (age range, 37 to 78 years) participated. DMP444 imaging was positive on SPECT in five patients, and all had definite endocarditis (affecting both prosthetic and native valves). Eleven patients were DMP444 negative, seven with no proof of IE. The remaining four patients were classified as having IE, but three had been receiving adequate intravenous antibiotic regimens for > or = 2 weeks at the time of scintigraphy and one had Q-fever endocarditis. CONCLUSIONS DMP444 SPECT allows in vivo visualization of IE if it is performed within 1 to 2 weeks after the start of antibiotic treatment. Given the high affinity of DMP444 for activated platelets, the results indicate the involvement of activated platelets in early IE.
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Kerrigan SW, Douglas I, Wray A, Heath J, Byrne MF, Fitzgerald D, Cox D. A role for glycoprotein Ib in Streptococcus sanguis-induced platelet aggregation. Blood 2002; 100:509-16. [PMID: 12091342 DOI: 10.1182/blood.v100.2.509] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Numerous studies have implicated bacteria in cardiovascular disease, but there is a paucity of information on the mechanism involved. In this study we show how the common oral bacterium Streptococcus sanguis can directly interact with platelets, resulting in activation and aggregate formation. Platelet aggregation was dependent on glycoprotein IIb/IIIa (GPIIb/IIIa) and thromboxane. Platelets could also directly bind to S sanguis, but this interaction was not inhibited by GPIIb/IIIa antagonists. Antibodies to GPIb could inhibit both platelet aggregation and platelet adhesion to bacteria. This suggested a direct interaction between GPIb and S sanguis; however, this interaction did not require von Willebrand factor, the normal ligand for GPIb. By use of a range of monoclonal antibodies to GPIb and the enzyme mocharagin, which cleaves GPIb at amino acid 282, the interaction was localized to a region within the N-terminal 1-225 portion of GPIbalpha. Furthermore S sanguis failed to induce aggregation of platelets from a patient with Bernard-Soulier disease, the organism bound to Chinese hamster ovary cells transfected with the GPIbalpha gene but did not bind to mock-transfected cells and biotin-labeled S sanguis cells bound to purified GPIb in ligand blots. It is suggested that the interaction between S sanguis and GPIb is important in the pathogenesis of infective endocarditis and may also play a contributory role in some cases of myocardial infarction.
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Affiliation(s)
- Steven W Kerrigan
- Department of Clinical Pharmacology, Royal College of Surgeons in Ireland, Dublin, Ireland
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22
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Krijgsveld J, Zaat SA, Meeldijk J, van Veelen PA, Fang G, Poolman B, Brandt E, Ehlert JE, Kuijpers AJ, Engbers GH, Feijen J, Dankert J. Thrombocidins, microbicidal proteins from human blood platelets, are C-terminal deletion products of CXC chemokines. J Biol Chem 2000; 275:20374-81. [PMID: 10877842 DOI: 10.1074/jbc.275.27.20374] [Citation(s) in RCA: 236] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Antibacterial proteins are components of the innate immune system found in many organisms and produced by a variety of cell types. Human blood platelets contain a number of antibacterial proteins in their alpha-granules that are released upon thrombin activation. The present study was designed to purify these proteins obtained from human platelets and to characterize them chemically and biologically. Two antibacterial proteins were purified from platelet granules in a two-step protocol using cation exchange chromatography and continuous acid urea polyacrylamide gel electrophoresis and were designated thrombocidin (TC)-1 and TC-2. Characterization of these proteins using mass spectrometry and N-terminal sequencing revealed that TC-1 and TC-2 are variants of the CXC chemokines neutrophil-activating peptide-2 and connective tissue-activating peptide-III, respectively. TC-1 and TC-2 differ from these chemokines by a C-terminal truncation of 2 amino acids. Both TCs, but not neutrophil-activating peptide-2 and connective tissue-activating peptide-III, were bactericidal for Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Lactococcus lactis and fungicidal for Cryptococcus neoformans. Killing of B. subtilis by either TC appeared to be very rapid. Because TCs were unable to dissipate the membrane potential of L. lactis, the mechanism of TC-mediated killing most probably does not involve pore formation.
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Affiliation(s)
- J Krijgsveld
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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23
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Meyer MW, Gong K, Herzberg MC. Streptococcus sanguis-induced platelet clotting in rabbits and hemodynamic and cardiopulmonary consequences. Infect Immun 1998; 66:5906-14. [PMID: 9826372 PMCID: PMC108748 DOI: 10.1128/iai.66.12.5906-5914.1998] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1998] [Accepted: 09/11/1998] [Indexed: 11/20/2022] Open
Abstract
By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits. The extent of hemodynamic and cardiopulmonary changes and the fate of circulating platelets were Agg+ strain dose dependent. Within 45 to 50 s of the start of infusion, 40 x 10(8) CFU of the Agg+ strain caused increased blood pressure. Thirty seconds after infusion, other changes occurred. Intermittent electrocardiographic abnormalities (13 of 15 rabbits), ST-segment depression (10 of 15 rabbits), and preventricular contractions (7 of 15 rabbits) manifested at 3 to 7 min, with frequencies dose dependent. Respiratory rate and cardiac contractility increased during this phase. Blood catecholamine concentration, thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and ventricular axis deviation also showed dose dependency. Rabbits were unaffected by inoculation of an Agg- strain. Therefore, Agg+ S. sanguis induced platelet aggregation in vitro. Platelet clots caused hemodynamic changes, acute pulmonary hypertension, and cardiac abnormalities, including ischemia.
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Affiliation(s)
- M W Meyer
- School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
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24
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Sullam PM, Hyun WC, Szöllösi J, Dong JF, Foss WM, López JA. Physical proximity and functional interplay of the glycoprotein Ib-IX-V complex and the Fc receptor FcgammaRIIA on the platelet plasma membrane. J Biol Chem 1998; 273:5331-6. [PMID: 9478992 DOI: 10.1074/jbc.273.9.5331] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although the glycoprotein (GP) Ib-IX-V complex and FcgammaRIIA are distinct platelet membrane receptors, previous studies have suggested that these structures may be co-localized. To determine more directly the proximity of GP Ib-IX-V and FcgammaRIIA, we assessed the effects of anti-GP Ibalpha monoclonal antibodies on FcgammaRIIA-mediated platelet aggregation and on the direct binding of polymeric IgG to human platelets. In addition, we directly examined the proximity of FcgammaRII and GP Ib-IX-V using flow cytometric fluorescence energy transfer and immunoprecipitation studies. Preincubation of platelets with either of two monoclonal antibodies (AN51 or SZ2) directed against GP Ibalpha completely blocked platelet aggregation by polymeric IgG. Similarly, these antibodies totally inhibited platelet aggregation by two strains of viridans group streptococci known to induce aggregation via FcgammaRIIA. In addition, AN51 and SZ2 significantly reduced the binding of polymeric IgG to washed fixed platelets. When assessed by flow cytometry, significant levels of bidirectional energy transfer were detected between FcgammaRIIA and GP Ibalpha, indicating a physical proximity of less than 10 nm between these receptors. This energy transfer was not due to high receptor density, because no homoassociative energy transfer was seen. Moreover, immunoprecipitation of FcgammaRIIA from platelet lysates also co-precipitated GP Ibalpha. These results indicate that GP Ibalpha and FcgammaRIIA are co-localized on the platelet membrane and that this association is not random.
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Affiliation(s)
- P M Sullam
- Department of Medicine, University of California, San Francisco and Veterans Affairs Medical Center, San Francisco, California 94121, USA.
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25
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Herzberg MC, Meyer MW, Kiliç A, Tao L. Host-pathogen interactions in bacterial endocarditis: streptococcal virulence in the host. Adv Dent Res 1997; 11:69-74. [PMID: 9524444 DOI: 10.1177/08959374970110011901] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To identify streptococcal genes that are expressed during experimental endocarditis, we developed a promoter-less dual reporter gene-fusion (amy, cat) plasmid, pAK36. Chromosomal DNA from S. gordonii V288 was digested with Sau3A1. The resulting fragments were ligated into pAK36. Following transformation into S. gordonii, the library of random gene fusion clones was inoculated into a rabbit to induce experimental endocarditis. Chloramphenicol treatment effected positive selection. Upon euthanization of the rabbits, the valvular vegetations were excised in a sterile field. Surviving clones were isolated and screened in vitro for chloramphenicol sensitivity and negative amylase activity. From the 48 randomly picked, double-negative clones, DNA was isolated and analyzed by Southern hybridization with labeled pAK36 probe. Different insertion patterns were identified, suggesting that no fewer than 13 S. gordonii genes were induced. Therefore, S. gordonii genes are induced during experimental endocarditis, which may contribute to virulence.
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Affiliation(s)
- M C Herzberg
- Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis 55455, USA
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26
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Herzberg MC. Platelet-streptococcal interactions in endocarditis. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1996; 7:222-36. [PMID: 8909879 DOI: 10.1177/10454411960070030201] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Infective endocarditis is characterized by the formation of septic masses of platelets on the surfaces of heart valves and is most commonly caused by viridans streptococci. Streptococcal virulence in endocarditis involves factors that promote infectivity and pathogenicity. Adhesins and exopolysaccharide (glycocalyx) contribute to infectivity. Although many factors may contribute to pathogenicity, the platelet aggregation-associated protein (PAAP) of Streptococcus sanguis contributes directly to the development of experimental endocarditis. PAAP is synthesized as a rhamnose-rich glycoprotein of 115 kDa and contains a collagen-like platelet-interactive domain, pro-gly-glu-gln-gly-pro-lys. Expressed on the cell wall of platelet aggregation-inducing strains (Agg+) of S. sanguis, PAAP apparently interacts with a signal-transducing receptor complex on platelets, which includes a novel 175-kDa alpha 2-integrin-associated protein and a 65-kDa collagen-binding component. From available data, the role of PAAP in the pathogenesis of experimental endocarditis may be explained by a proposed mechanistic model. On injured heart valves, PAAP first enhances platelet accumulation into a fibrin-enmeshed thrombus (vegetation), within which S. sanguis colonizes. Colonizing bacteria must resist platelet microbicidal protein (PMPR). The aggregation of platelets on the heart valve may be potentiated by an ectoATPase expressed on the surface of the S. sanguis and platelet alpha-adrenoreceptors that respond to endogenous catecholamines. The expression of PAAP may be modified during infection. Collagen is exposed on damaged heart valves; fever (heat shock) occurs during endocarditis. In response to heat shock or collagen in vitro, PAAP expression is altered. After colonization, streptococcal exotoxin(s) may cause fever. Proteases and other enzymes from streptococci and host sources may directly destroy the heart valves. When PAAP is unexpressed or neutralized with specific antibodies, experimental endocarditis runs a milder course and vegetations are smaller. The data suggest strongly, therefore, that the role of PAAP may overlap the colonization function of putative adhesins such as FimA or SsaB. Finally, PAAP also contributes to the development of the characteristic septic mural thrombus (vegetation) of infective endocarditis and the signs of valvular pathology.
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Affiliation(s)
- M C Herzberg
- Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneopolis 55455, USA
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27
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Homer KA, Kelley S, Hawkes J, Beighton D, Grootveld MC. Metabolism of glycoprotein-derived sialic acid and N-acetylglucosamine by Streptococcus oralis. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 5):1221-1230. [PMID: 8704962 DOI: 10.1099/13500872-142-5-1221] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nine strains of Streptococcus oralis, isolated from blood cultures of patients with infective endocarditis or from the oral cavity as part of the normal flora, were examined for their ability to elaborate sialidase (neuraminidase) and N-acetylglucosaminidase, enzymes which are involved in the degradation of glycoproteins. Both glycosidases were induced when bacteria were grown in a minimal medium supplemented with porcine gastric mucin, a model glycoprotein, and repressed when growth occurred in the presence of glucose. Cell-free extracts mucin-grown cultures expressed elevated levels of N-acetylneuraminate pyruvate-lyase (the first intracellular enzyme in the pathway of N-acetylneuraminate catabolism), N-acetylglucosamine (glcNAc)-6-phosphate deacetylase and glucosamine-6-phosphate deaminase (enzymes involved in the intracellular catabolism of GlcNAc 6-phosphate); activity of each of these intracellular enzymes was markedly repressed when bacteria were grown in media supplemented with alpha 1-acid glycoprotein, a major component of human plasma. Cells from these cultures expressed high levels of sialidase, N-acetylglucosaminidase, and the intracellular enzymes involved in the catabolism of N-acetyl-sugars released by action of these glycosidases. High-resolution 1H-NMR spectroscopy of spent culture supernatants revealed that sialic acid and GlcNAc residues of the molecularly mobile oligosaccharide side-chains of alpha 1-acid glycoprotein had been hydrolysed and the released sugars internalized by the bacteria. These data indicate that S. oralis has the ability to hydrolyse constituents of oligosaccharide side-chains of host-derived glycoproteins and to utilize simultaneously these released carbohydrates. The biochemical characteristics induced by the growth of S. oralis on glycoproteins may play a role in the survival and persistence of these bacteria at the infection site in vivo.
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Affiliation(s)
- K A Homer
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - S Kelley
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - J Hawkes
- Department of Chemistry, King's College (Strand Campus), University of London, The Strand, London WC2R 2LS, UK
| | - D Beighton
- Joint Microbiology Research Unit, King's College School of Medicine and Dentistry, Faculty of Clinical Dentistry, Caldecot Road, London SE5 9RW, UK
| | - M C Grootveld
- Inflammation Research Group, The London Hospital Medical College, Ashfield Street, London E1 2AD, UK
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Auclair F. Update on pathogenesis of infective endocarditis. Cardiovasc Pathol 1995; 4:265-8. [DOI: 10.1016/1054-8807(95)00053-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/1995] [Accepted: 06/07/1995] [Indexed: 10/17/2022] Open
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29
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Dobos KM, Swiderek K, Khoo KH, Brennan PJ, Belisle JT. Evidence for glycosylation sites on the 45-kilodalton glycoprotein of Mycobacterium tuberculosis. Infect Immun 1995; 63:2846-53. [PMID: 7622204 PMCID: PMC173386 DOI: 10.1128/iai.63.8.2846-2853.1995] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The occurrence of glycosylated proteins in Mycobacterium tuberculosis has been widely reported. However, unequivocal proof for the presence of true glycosylated amino acids within these proteins has not been demonstrated, and such evidence is essential because of the predominance of soluble lipoglycans and glycolipids in all mycobacterial extracts. We have confirmed the presence of several putative glycoproteins in subcellular fractions of M. tuberculosis by reaction with the lectin concanavalin A. One such product, with a molecular mass of 45 kDa, was purified from the culture filtrate. Compositional analysis demonstrated that the protein was rich in proline and that mannose, galactose, glucose, and arabinose together represented about 4% of the total mass. The 45-kDa glycoprotein was subjected to proteolytic digestion with either the Asp-N or the Glu-C endopeptidase or subtilisin, peptides were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and glycopeptides were identified by reaction with concanavalin A. Peptides were further separated, and when they were analyzed by liquid chromatography-electrospray mass spectrometry for neutral losses of hexoses (162 mass units), four peptides were identified, indicating that these were glycosylated with hexose residues. One peptide, with an average molecular mass of 1,516 atomic mass units (AMU), exhibited a loss of two hexose units. The N-terminal sequence of the 1,516-AMU glycopeptide was determined to be DPEPAPPVP, which was identical to the sequence of the amino terminus of the mature protein, DPEPAP PVPXTA. Furthermore, analysis of the glycopeptide by secondary ion mass spectrometry demonstrated that the complete sequence of the glycopeptide was DPEPAPPVPTTA. From this, it was determined that the 10th amino acid, threonine, was O-glycosidically linked to a disaccharide composed of two hexose residues, probably mannose. This report establishes that true, O-glycosylated proteins exist in mycobacteria.
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Affiliation(s)
- K M Dobos
- Department of Microbiology, Colorado State University, Fort Collins 80523, USA
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