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Jia Y, Zhang L, Xu J, Xiang L. Recent advances in cell membrane camouflaged nanotherapeutics for the treatment of bacterial infection. Biomed Mater 2024; 19:042006. [PMID: 38697197 DOI: 10.1088/1748-605x/ad46d4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 05/01/2024] [Indexed: 05/04/2024]
Abstract
Infectious diseases caused by bacterial infections are common in clinical practice. Cell membrane coating nanotechnology represents a pioneering approach for the delivery of therapeutic agents without being cleared by the immune system in the meantime. And the mechanism of infection treatment should be divided into two parts: suppression of pathogenic bacteria and suppression of excessive immune response. The membrane-coated nanoparticles exert anti-bacterial function by neutralizing exotoxins and endotoxins, and some other bacterial proteins. Inflammation, the second procedure of bacterial infection, can also be suppressed through targeting the inflamed site, neutralization of toxins, and the suppression of pro-inflammatory cytokines. And platelet membrane can affect the complement process to suppress inflammation. Membrane-coated nanoparticles treat bacterial infections through the combined action of membranes and nanoparticles, and diagnose by imaging, forming a theranostic system. Several strategies have been discovered to enhance the anti-bacterial/anti-inflammatory capability, such as synthesizing the material through electroporation, pretreating with the corresponding pathogen, membrane hybridization, or incorporating with genetic modification, lipid insertion, and click chemistry. Here we aim to provide a comprehensive overview of the current knowledge regarding the application of membrane-coated nanoparticles in preventing bacterial infections as well as addressing existing uncertainties and misconceptions.
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Affiliation(s)
- Yinan Jia
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Li Zhang
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Junhua Xu
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Lin Xiang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, People's Republic of China
- Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, People's Republic of China
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Ruan Q, Guan P, Qi W, Li J, Xi M, Xiao L, Zhong S, Ma D, Ni J. Porphyromonas gingivalis regulates atherosclerosis through an immune pathway. Front Immunol 2023; 14:1103592. [PMID: 36999040 PMCID: PMC10043234 DOI: 10.3389/fimmu.2023.1103592] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/01/2023] [Indexed: 03/15/2023] Open
Abstract
Atherosclerosis (AS) is a chronic inflammatory disease, involving a pathological process of endothelial dysfunction, lipid deposition, plaque rupture, and arterial occlusion, and is one of the leading causes of death in the world population. The progression of AS is closely associated with several inflammatory diseases, among which periodontitis has been shown to increase the risk of AS. Porphyromonas gingivalis (P. gingivalis), presenting in large numbers in subgingival plaque biofilms, is the “dominant flora” in periodontitis, and its multiple virulence factors are important in stimulating host immunity. Therefore, it is significant to elucidate the potential mechanism and association between P. gingivalis and AS to prevent and treat AS. By summarizing the existing studies, we found that P. gingivalis promotes the progression of AS through multiple immune pathways. P. gingivalis can escape host immune clearance and, in various forms, circulate with blood and lymph and colonize arterial vessel walls, directly inducing local inflammation in blood vessels. It also induces the production of systemic inflammatory mediators and autoimmune antibodies, disrupts the serum lipid profile, and thus promotes the progression of AS. In this paper, we summarize the recent evidence (including clinical studies and animal studies) on the correlation between P. gingivalis and AS, and describe the specific immune mechanisms by which P. gingivalis promotes AS progression from three aspects (immune escape, blood circulation, and lymphatic circulation), providing new insights into the prevention and treatment of AS by suppressing periodontal pathogenic bacteria.
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Affiliation(s)
- Qijun Ruan
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Peng Guan
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Weijuan Qi
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Jiatong Li
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Mengying Xi
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Limin Xiao
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Sulan Zhong
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Dandan Ma
- Department of Endodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
- *Correspondence: Dandan Ma, ; Jia Ni,
| | - Jia Ni
- Department of Periodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
- *Correspondence: Dandan Ma, ; Jia Ni,
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Hijacking host components for bacterial biofilm formation: An advanced mechanism. Int Immunopharmacol 2021; 103:108471. [PMID: 34952466 DOI: 10.1016/j.intimp.2021.108471] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Biofilm is a community of bacteria embedded in the extracellular matrix that accounts for 80% of bacterial infections. Biofilm enables bacterial cells to provide particular conditions and produce virulence determinants in response to the unavailability of micronutrients and local oxygen, resulting in their resistance to various antibacterial agents. Besides, the human immune reactions are not completely competent in the elimination of biofilm. Most importantly, the growing body of evidence shows that some bacterial spp. use a variety of mechanisms by which hijack the host components to form biofilm. In this regard, host components, such as DNA, hyaluronan, collagen, fibronectin, mucin, oligosaccharide moieties, filamentous polymers (F-actin), plasma, platelets, keratin, sialic acid, laminin, vitronectin, C3- and C4- binding proteins, antibody, proteases, factor I, factor H, and acidic proline-rich proteins have been reviewed. Hence, the characterization of interactions between bacterial biofilm and the host would be critical to effectively address biofilm-associated infections. In this paper, we review the latest information on the hijacking of host factors by bacteria to form biofilm.
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Tokarz-Deptuła B, Palma J, Baraniecki Ł, Stosik M, Kołacz R, Deptuła W. What Function Do Platelets Play in Inflammation and Bacterial and Viral Infections? Front Immunol 2021; 12:770436. [PMID: 34970260 PMCID: PMC8713818 DOI: 10.3389/fimmu.2021.770436] [Citation(s) in RCA: 1] [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: 09/03/2021] [Accepted: 11/22/2021] [Indexed: 12/15/2022] Open
Abstract
The article presents the function of platelets in inflammation as well as in bacterial and viral infections, which are the result of their reaction with the endovascular environment, including cells of damaged vascular endothelium and cells of the immune system. This role of platelets is conditioned by biologically active substances present in their granules and in their specific structures - EV (extracellular vesicles).
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Affiliation(s)
| | - Joanna Palma
- Department of Biochemical Sciences, Pomeranian Medical University, Szczecin, Poland
| | | | - Michał Stosik
- Institute of Biological Science, Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra, Poland
| | - Roman Kołacz
- Institute of Veterinary Medicine, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Wiesław Deptuła
- Institute of Veterinary Medicine, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Toruń, Poland
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Gusdon AM, Farrokh S, Grotta JC. Antithrombotic Therapy for Stroke Patients with Cardiovascular Disease. Semin Neurol 2021; 41:365-387. [PMID: 33851394 DOI: 10.1055/s-0041-1726331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Prevention of ischemic stroke relies on the use of antithrombotic medications comprising antiplatelet agents and anticoagulation. Stroke risk is particularly high in patients with cardiovascular disease. This review will focus on the role of antithrombotic therapies in the context of different types of cardiovascular disease. We will discuss oral antiplatelet medications and both IV and parental anticoagulants. Different kinds of cardiovascular disease contribute to stroke via distinct pathophysiological mechanisms, and the optimal treatment for each varies accordingly. We will explore the mechanism of stroke and evidence for antithrombotic therapy in the following conditions: atrial fibrillation, prosthetic heart values (mechanical and bioprosthetic), aortic arch atherosclerosis, congestive heart failure (CHF), endocarditis (infective and nonbacterial thrombotic endocarditis), patent foramen ovale (PFO), left ventricular assist devices (LVAD), and extracorporeal membrane oxygenation (ECMO). While robust data exist for antithrombotic use in conditions such as atrial fibrillation, optimal treatment in many situations remains under active investigation.
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Affiliation(s)
- Aaron M Gusdon
- Department of Neurosurgery, UTHealth Neurosciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, Texas
| | - Salia Farrokh
- Division of Neurocritical Care, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - James C Grotta
- Mobile Stroke Unit, Memorial Hermann Hospital, Texas Medical Center, Houston
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Porphyromonas gingivalis, Periodontal and Systemic Implications: A Systematic Review. Dent J (Basel) 2019; 7:dj7040114. [PMID: 31835888 PMCID: PMC6960968 DOI: 10.3390/dj7040114] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 11/28/2019] [Accepted: 12/09/2019] [Indexed: 12/26/2022] Open
Abstract
In recent scientific literature, oral infections and systemic manifestations, or correlations between oral health and systemic diseases are a topic of discussion. Porphyromonas gingivalis is one of the bacteria implicated in the biofilm formation of bacterial plaque, and plays an important role in the progression of periodontal disease. In this systematic review authors have evaluated the literature of the last 10 years on P. gingivalis and all the systemic implications proven. This study therefore evaluates all the districts of the organism in which this bacterium may have implications. From the results it emerges that P. gingivalis has implications in the onset of different systemic pathologies, including rheumatoid arthritis, cardiovascular pathologies, and neurodegenerative pathologies. Surely, understanding the mechanisms of diffusion of this bacterium, it would be possible to prevent a series of pathologies. Thus, putting the dentist clinician at the center of prevention for these diseases.
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Rosas-Martínez M, Gutiérrez-Venegas G. Myricetin Inhibition of Peptidoglycan-Induced COX-2 Expression in H9c2 Cardiomyocytes. Prev Nutr Food Sci 2019; 24:202-209. [PMID: 31328126 PMCID: PMC6615347 DOI: 10.3746/pnf.2019.24.2.202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 05/23/2019] [Indexed: 11/06/2022] Open
Abstract
Peptidoglycan (PGN) is a cell wall constituent in dental plaque bacteria that triggers inflammatory responses. PGN binds Toll-like receptors, leading to increases in prostaglandin E2 and interleukin-1β, which play crucial roles in the inflammatory response and tissue destruction. Dental surgery can give plaque bacteria access to blood circulation, thereby creating a risk of septic inflammation of the endocardium. Plant-derived flavonoids have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we investigated the effects of flavonoid myricetin on expression of cyclooxygenase 2 (COX-2) in the H9c2 cells treated with PGN from Streptococcus sanguinis, a bacterial constituent of dental plaque associated with infective endocarditis. Myricetin exposure resulted in dose-dependent suppression of PGN-induced COX-2 expression, diminished phosphorylation of p38, extracellular signal regulated kinase 1/2, and c-Jun N-terminal kinase, and reduced IκB-α degradation, consistent with decreased COX-2 activity. In conclusion, the aforementioned results suggest that myricetin is useful for moderating the inflammatory response in infective endocarditis.
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Affiliation(s)
- Marisol Rosas-Martínez
- Biochemistry Laboratory of the Division of Graduate Studies and Research, Faculty of Dentistry, National Autonomous University of Mexico, Mexico 04510, Mexico
| | - Gloria Gutiérrez-Venegas
- Biochemistry Laboratory of the Division of Graduate Studies and Research, Faculty of Dentistry, National Autonomous University of Mexico, Mexico 04510, Mexico
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Haworth JA, Jenkinson HF, Petersen HJ, Back CR, Brittan JL, Kerrigan SW, Nobbs AH. Concerted functions of Streptococcus gordonii surface proteins PadA and Hsa mediate activation of human platelets and interactions with extracellular matrix. Cell Microbiol 2017; 19:e12667. [PMID: 27616700 PMCID: PMC5574023 DOI: 10.1111/cmi.12667] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/23/2016] [Accepted: 09/07/2016] [Indexed: 12/17/2022]
Abstract
A range of Streptococcus bacteria are able to interact with blood platelets to form a thrombus (clot). Streptococcus gordonii is ubiquitous within the human oral cavity and amongst the common pathogens isolated from subjects with infective endocarditis. Two cell surface proteins, Hsa and Platelet adherence protein A (PadA), in S. gordonii mediate adherence and activation of platelets. In this study, we demonstrate that PadA binds activated platelets and that an NGR (Asparagine-Glycine-Arginine) motif within a 657 amino acid residue N-terminal fragment of PadA is responsible for this, together with two other integrin-like recognition motifs RGT and AGD. PadA also acts in concert with Hsa to mediate binding of S. gordonii to cellular fibronectin and vitronectin, and to promote formation of biofilms. Evidence is presented that PadA and Hsa are each reliant on the other's active presentation on the bacterial cell surface, suggesting cooperativity in functions impacting both colonization and pathogenesis.
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Affiliation(s)
| | | | | | | | - Jane L. Brittan
- School of Oral and Dental SciencesUniversity of BristolBristolUK
| | - Steve W. Kerrigan
- Cardiovascular Infection GroupRoyal College of Surgeons in IrelandDublin 2Ireland
| | - Angela H. Nobbs
- School of Oral and Dental SciencesUniversity of BristolBristolUK
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Benedyk M, Mydel PM, Delaleu N, Płaza K, Gawron K, Milewska A, Maresz K, Koziel J, Pyrc K, Potempa J. Gingipains: Critical Factors in the Development of Aspiration Pneumonia Caused by Porphyromonas gingivalis. J Innate Immun 2015; 8:185-98. [PMID: 26613585 DOI: 10.1159/000441724] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/16/2015] [Indexed: 01/06/2023] Open
Abstract
Aspiration pneumonia is a life-threatening infectious disease often caused by oral anaerobic and periodontal pathogens such as Porphyromonas gingivalis. This organism produces proteolytic enzymes, known as gingipains, which manipulate innate immune responses and promote chronic inflammation. Here, we challenged mice with P. gingivalis W83 and examined the role of gingipains in bronchopneumonia, lung abscess formation, and inflammatory responses. Although gingipains were not required for P. gingivalis colonization and survival in the lungs, they were essential for manifestation of clinical symptoms and infection-related mortality. Pathologies caused by wild-type (WT) P. gingivalis W83, including hemorrhage, necrosis, and neutrophil infiltration, were absent from lungs infected with gingipain-null isogenic strains or WT bacteria preincubated with gingipain-specific inhibitors. Damage to lung tissue correlated with systemic inflammatory responses, as manifested by elevated levels of TNF, IL-6, IL-17, and C-reactive protein. These effects were unequivocally dependent on gingipain activity. Gingipain activity was also implicated in the observed increase in IL-17 in lung tissues. Furthermore, gingipains increased platelet counts in the blood and activated platelets in the lungs. Arginine-specific gingipains made a greater contribution to P. gingivalis-related morbidity and mortality than lysine-specific gingipains. Thus, inhibition of gingipain may be a useful adjunct treatment for P. gingivalis-mediated aspiration pneumonia.
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Affiliation(s)
- Małgorzata Benedyk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
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Barnabé M, Saraceni CHC, Dutra-Correa M, Suffredini IB. The influence of Brazilian plant extracts on Streptococcus mutans biofilm. J Appl Oral Sci 2015; 22:366-72. [PMID: 25466471 PMCID: PMC4245747 DOI: 10.1590/1678-775720140085] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/20/2014] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. OBJECTIVE Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. MATERIAL AND METHODS Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. RESULTS Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry.
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Affiliation(s)
- Michele Barnabé
- School of Dentistry, Health Sciences Institute, Paulista University, São Paulo, SP, Brazil
| | | | | | - Ivana Barbosa Suffredini
- Center for Research in Biodiversity, Extraction Laboratory, Paulista University, São Paulo, SP, Brazil
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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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Garraud O, Cognasse F. Are Platelets Cells? And if Yes, are They Immune Cells? Front Immunol 2015; 6:70. [PMID: 25750642 PMCID: PMC4335469 DOI: 10.3389/fimmu.2015.00070] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/03/2015] [Indexed: 02/06/2023] Open
Abstract
Small fragments circulating in the blood were formally identified by the end of the nineteenth century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the twentieth century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such, however, they were acknowledged as immunizing (to specific HPA and HLA markers): the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as 1930s, platelets entered the arsenal of medicines were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an “immune cell”? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages). The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of immune cells.
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Affiliation(s)
- Olivier Garraud
- Institut National de la Transfusion Sanguine , Paris , France ; EA3064, Université de Lyon , Saint-Etienne , France
| | - Fabrice Cognasse
- EA3064, Université de Lyon , Saint-Etienne , France ; Etablissement Français du Sang Auvergne-Loire , Saint-Etienne , France
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Hao HZ, He AD, Wang DC, Yin Z, Zhou YJ, Liu G, Liang ML, Da XW, Yao GQ, Xie W, Xiang JZ, Ming ZY. Antiplatelet activity of loureirin A by attenuating Akt phosphorylation: In vitro studies. Eur J Pharmacol 2015; 746:63-9. [PMID: 25445049 DOI: 10.1016/j.ejphar.2014.10.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/31/2014] [Accepted: 10/31/2014] [Indexed: 02/05/2023]
Abstract
Loureirin A is a flavonoid extracted from Dragon׳s Blood that has been used to promote blood circulation and remove stasis in Chinese traditional medicine. However, the mechanisms of these effects are not fully understood. We explored the anti-platelet activity and underlying mechanism of loureirin A in vitro. Our results indicated that loureirin A negatively affected agonist-induced platelet aggregation such as collagen, collagen-related peptide (CRP), ADP and thrombin. Loureirin A inhibited collagen-induced platelet ATP secretion and thrombin-stimulated P-selectin expression in a dose-dependent manner. Platelet spreading on immobilized fibrinogen was significantly impaired in the presence of loureirin A. Immunoblotting analysis indicated that 100μM of loureirin A almost completely eliminated collagen-induced Akt phosphorylation at Ser473. Interestingly, a submaximal dose (50μM) of loureirin A had an additive inhibitory effect with the phosphoinositide 3-kinase (PI3K) inhibitor Ly294002 on collage-induced Akt phosphorylation in platelets. Taken together, loureirin A had an inhibitory effect on platelet activation, perhaps through an impairment of PI3K/Akt signaling.
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Affiliation(s)
- Hong-Zhen Hao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China; Department of Pharmacy, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Ao-Di He
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Dao-Chun Wang
- Department of Traditional Chinese Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Zhao Yin
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Ya-Jun Zhou
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Gang Liu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Ming-Lu Liang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Xing-Wen Da
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Guang-Qiang Yao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Wen Xie
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Ji-Zhou Xiang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Zhang-Yin Ming
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China.
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Jung CJ, Yeh CY, Hsu RB, Lee CM, Shun CT, Chia JS. Endocarditis pathogen promotes vegetation formation by inducing intravascular neutrophil extracellular traps through activated platelets. Circulation 2014; 131:571-81. [PMID: 25527699 DOI: 10.1161/circulationaha.114.011432] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Endocarditis-inducing streptococci form multilayered biofilms in complex with aggregated platelets on injured heart valves, but the host factors that interconnect and entrap these bacteria-platelet aggregates to promote vegetation formation were unclear. METHODS AND RESULTS In a Streptococcus mutans endocarditis rat model, we identified layers of neutrophil extracellular traps interconnecting and entrapping bacteria-platelet aggregates inside vegetation that could be reduced significantly in size along with diminished colonizing bacteria by prophylaxis with intravascular DNase I alone. The combination of activated platelets and specific immunoglobulin G-adsorbed bacteria are required to induce the formation of neutrophil extracellular traps through multiple activation pathways. Bacteria play key roles in coordinating the signaling through spleen tyrosine kinase, Src family kinases, phosphatidylinositol-3-kinase, and p38 mitogen-activated protein kinase pathways to upregulate the expression of P-selectin in platelets, while inducing reactive oxygen species-dependent citrullination in the arm of neutrophils. Neutrophil extracellular traps in turn serve as the scaffold to further enhance and entrap bacteria-platelet aggregate formation and expansion. CONCLUSIONS Neutrophil extracellular traps promote and expand vegetation formation through enhancing and entrapping bacteria-platelet aggregates on the injured heart valves.
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Affiliation(s)
- Chiau-Jing Jung
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.)
| | - Chiou-Yueh Yeh
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.)
| | - Ron-Bin Hsu
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.)
| | - Chii-Ming Lee
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.)
| | - Chia-Tung Shun
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.)
| | - Jean-San Chia
- From the Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-J.J., J.-S.C.); Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan (C.-Y.Y., J.-S.C.); Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (R.-B.H.); Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-M.L.); and Department of Forensic Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan (C.-T.S.).
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15
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Cognasse F, Hamzeh-Cognasse H, Chabert A, Jackson E, Arthaud CA, Garraud O, McNicol A. Streptococcus sanguinis-induced cytokine and matrix metalloproteinase-1 release from platelets. BMC Immunol 2014; 15:15. [PMID: 24755160 PMCID: PMC3998947 DOI: 10.1186/1471-2172-15-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 04/07/2014] [Indexed: 01/01/2023] Open
Abstract
Background Streptococcus sanguinis (S.sanguinis), a predominant bacterium in the human oral cavity, has been widely associated with the development of infective endocarditis. Platelets play both a haemostatic function and can influence both innate and adaptive immune responses. Previous studies have shown that S.sanguinis can interact with, and activate, platelets. Results The aim of this study was to determine whether S.sanguinis stimulates the release of matrix metalloproteinases (MMPs) 1, 2 and 9 and the pro-inflammatory mediators SDF-1, VEGF and sCD40L, from platelets and to subsequently pharmacologically address the release mechanism (s). S.sanguinis stimulated the release of MMP-1, SDF-1, VEGF and sCD40L from platelets and inhibitors of cyclooxygenase and phosphatidylinositol 3-kinase, and antagonists of the αIIbβ3 integrin and glycoprotein Ib, each inhibited the secretion of all factors. Conclusions Therefore the release of MMP-1, SDF-1, VEGF and sCD40L occurs late in the platelet response to S.sanguinis and highlights the complex intracellular signalling pathways stimulated in response to S.sanguinis which lead to haemostasis, MMP and pro-inflammatory mediator secretion.
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Affiliation(s)
- Fabrice Cognasse
- Etablissement Français du Sang (EFS) Auvergne-Loire, Saint-Etienne, France.
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Dénes Á, Pradillo JM, Drake C, Sharp A, Warn P, Murray KN, Rohit B, Dockrell DH, Chamberlain J, Casbolt H, Francis S, Martinecz B, Nieswandt B, Rothwell NJ, Allan SM. Streptococcus pneumoniae worsens cerebral ischemia via interleukin 1 and platelet glycoprotein Ibα. Ann Neurol 2014; 75:670-83. [PMID: 24644058 DOI: 10.1002/ana.24146] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 03/17/2014] [Accepted: 03/17/2014] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Bacterial infection contributes to diverse noninfectious diseases and worsens outcome after stroke. Streptococcus pneumoniae, the most common infection in patients at risk of stroke, is a major cause of prolonged hospitalization and death of stroke patients, but how infection impacts clinical outcome is not known. METHODS We induced sustained pulmonary infection by a human S. pneumoniae isolate in naive and comorbid rodents to investigate the effect of infection on vascular and inflammatory responses prior to and after cerebral ischemia. RESULTS S. pneumoniae infection triggered atherogenesis, led to systemic induction of interleukin (IL) 1, and profoundly exacerbated (50-90%) ischemic brain injury in rats and mice, a response that was more severe in combination with old age and atherosclerosis. Systemic blockade of IL-1 with IL-1 receptor antagonist (IL-1Ra) fully reversed infection-induced exacerbation of brain injury and functional impairment caused by cerebral ischemia. We show that infection-induced systemic inflammation mediates its effects via increasing platelet activation and microvascular coagulation in the brain after cerebral ischemia, as confirmed by reduced brain injury in response to blockade of platelet glycoprotein (GP) Ibα. IL-1 and platelet-mediated signals converge on microglia, as both IL-1Ra and GPIbα blockade reversed the production of IL-1α by microglia in response to cerebral ischemia in infected animals. INTERPRETATION S. pneumoniae infection augments atherosclerosis and exacerbates ischemic brain injury via IL-1 and platelet-mediated systemic inflammation. These mechanisms may contribute to diverse cardio- and cerebrovascular pathologies in humans.
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Affiliation(s)
- Ádám Dénes
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom; Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary
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17
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Garraud O, Hamzeh-Cognasse H, Pozzetto B, Cavaillon JM, Cognasse F. Bench-to-bedside review: Platelets and active immune functions - new clues for immunopathology? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:236. [PMID: 23998653 PMCID: PMC4055978 DOI: 10.1186/cc12716] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Platelets display a number of properties besides the crucial function of repairing damaged vascular endothelium and stopping bleeding; these are exploited to benefit patients receiving platelet component transfusions, which might categorize them as innate immune cells. For example, platelets specialize in pro-inflammatory activities, and can secrete a large number of molecules, many of which display biological response modifier functions. Platelets also express receptors for non-self-infectious and possibly non-infectious danger signals, and can engage infectious pathogens by mechanisms barely explained beyond observation. This relationship with infectious pathogens may involve other innate immune cells, especially neutrophils. The sophisticated interplay of platelets with bacteria may culminate in sepsis, a severe pathology characterized by significant reductions in platelet count and platelet dysfunction. How this occurs is still not fully understood. Recent findings from in-depth platelet signaling studies reveal the complexity of platelets and some of the ways they evolve along the immune continuum, from beneficial functions exemplified in endothelium repair to deleterious immunopathology as in systemic inflammatory response syndrome and acute vascular diseases. This review discusses the extended role of platelets as immune cells to emphasize their interactions with infectious pathogens sensed as potentially dangerous.
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Abstract
Infective endocarditis (IE) is an uncommon infection, occurring as a complication in varying percentages of bacteremic episodes. The ability of an organism to cause endocarditis is the result of an interplay between the predisposing structural abnormalities of the cardiac valve for bacterial adherence, the adhesion of circulating bacteria to the valvular surface, and the ability of the adherent bacteria to survive on the surface and propagate as vegetation or systemic emboli. Certain bacteria, if present in the bloodstream, may colonize the initially sterile vegetation composed of fibrin and platelets; bacterial growth enlarges the vegetation, further impeding blood flow and inciting inflammation that involves the vegetation and adjacent endothelium. The true incidence of endocarditis complicating each of the bacterial species causing IE is difficult to estimate. About 20 %-30 % of individuals with community-acquired staphylococcal bacteremia develop IE [1, 2].
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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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20
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Jung CJ, Yeh CY, Shun CT, Hsu RB, Cheng HW, Lin CS, Chia JS. Platelets enhance biofilm formation and resistance of endocarditis-inducing streptococci on the injured heart valve. J Infect Dis 2012; 205:1066-75. [PMID: 22357661 DOI: 10.1093/infdis/jis021] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Infective endocarditis is a typical biofilm-associated infectious disease frequently caused by commensal streptococci, but the contribution of host factors in biofilm formation is unclear. We found that platelets are essential for in vitro biofilm formation by Streptococcus mutans or Streptococcus gordonii grown in human plasma. The biofilms were composed of bacterial floes embedded with platelet aggregates in layers, and a similar architecture was also detected in situ on the injured valves of a rat model of experimental endocarditis. Similar to planktonic cells, the streptococci in biofilms were also able to induce platelet aggregation, which facilitates multilayer biofilm formation. Entrapping of platelets directly enhances the resistance of streptococcal biofilms to clindamycin. Prophylactic antibiotics or aspirin can reduce but not prevent or abolish biofilm formation on injured heart valves. Therefore, the platelet is a host factor for commensal streptococci in the circulation to consolidate biofilm formation and protect bacteria against antibiotics.
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Affiliation(s)
- Chiau-Jing Jung
- Graduate Institute of Microbiology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan, ROC
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21
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McNicol A, Agpalza A, Jackson ECG, Hamzeh-Cognasse H, Garraud O, Cognasse F. Streptococcus sanguinis-induced cytokine release from platelets. J Thromb Haemost 2011; 9:2038-49. [PMID: 21824285 DOI: 10.1111/j.1538-7836.2011.04462.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND There is increasing evidence that both chronic and acute infections play a role in the development and progression of atherothrombotic disorders. One potential mechanism is the direct activation of platelets by bacteria. A wide range of bacterial species activate platelets through heterogeneous mechanisms. The oral micro-organism S. sanguinis stimulates platelet aggregation in vitro in a strain-dependent manner, although there are no reports of associated cytokine production. OBJECTIVE The aim of the present study was to determine whether platelet activation by S. sanguinis involved the release of pro-inflammatory and immune modulating factors, and whether activation was enhanced by epinephrine. METHODS AND RESULTS Four strains of S. sanguinis and one of S. gordonii stimulated the release of RANTES, PF4, sCD40L and PDGF-AB, whereas only one S. sanguinis strain caused the release of sCD62p. Epinephrine enhanced S. sanguinis-induced platelet aggregation and phosphorylation of phospholipase Cγ2 and Erk, but inhibited RANTES, PF4, sCD40L and PDGF-AB release. Wortmannin inhibited S. sanguinis-induced aggregation and release; however, only aggregation was partially reversed by epinephrine. CONCLUSIONS The present study demonstrates that platelets respond to S. sanguinis with both prothrombotic and pro-inflammatory/immune-modulating responses. Epinephrine, potentially released in response to infection and/or stress, can significantly enhance the prothrombotic response, thereby providing a putative link between bacteraemia and acute coronary events during stress. In contrast, epinephrine inhibited the pro-inflammatory/immune-modulating response by an undetermined mechanism.
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Affiliation(s)
- A McNicol
- Department of Oral Biology, University of Manitoba, Winnipeg, MB, Canada.
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22
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Verraedt E, Braem A, Chaudhari A, Thevissen K, Adams E, Van Mellaert L, Cammue BP, Duyck J, Anné J, Vleugels J, Martens JA. Controlled release of chlorhexidine antiseptic from microporous amorphous silica applied in open porosity of an implant surface. Int J Pharm 2011; 419:28-32. [DOI: 10.1016/j.ijpharm.2011.06.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 06/26/2011] [Accepted: 06/30/2011] [Indexed: 10/17/2022]
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Zähner D, Gandhi AR, Yi H, Stephens DS. Mitis group streptococci express variable pilus islet 2 pili. PLoS One 2011; 6:e25124. [PMID: 21966432 PMCID: PMC3178606 DOI: 10.1371/journal.pone.0025124] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 08/25/2011] [Indexed: 11/25/2022] Open
Abstract
Background Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. Methodology/Principal Findings PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. Conclusions/Significance This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits in the Mitis group streptococci.
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Affiliation(s)
- Dorothea Zähner
- Division of Infectious Diseases, Department of Medicine, Atlanta, Georgia, United States of America.
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Association of natural anti-platelet factor 4/heparin antibodies with periodontal disease. Blood 2011; 118:1395-401. [PMID: 21659541 DOI: 10.1182/blood-2011-03-342857] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Platelet factor 4 (PF4) and heparin (H) form PF4/H complexes, the target of the immune reaction in heparin-induced thrombocytopenia (HIT). HIT seems to be a secondary immune response as anti-PF4/H-IgG antibodies occur as early as day 4 of heparin treatment. This study investigated whether prevalent infections such as periodontitis may induce the PF4/H immune response as: (1) natural anti-PF4/H Abs are present in the normal population; (2) PF4 bound to bacteria exposes the same antigen(s) as PF4/H complexes; and (3) sepsis induces PF4/H Abs in mice. We found PF4 bound to periodontal pathogens (Aggregatibacter actinomycetemcomitans; Porphyromonas gingivalis) enabling subsequent binding of human anti-PF4/H Abs. The association of natural PF4/H Abs and periodontitis was assessed in a case-control study, enrolling individuals with natural anti-PF4/H Abs (n = 40 matched pairs), and in the cross-sectional population-based Study of Health in Pomerania (SHIP; n = 3500). Both studies showed a robust association between periodontitis and presence of anti-PF4/H Abs independent of inflammation markers (case-control study: lowest vs highest tertile, odds ratio, 7.12 [95% confidence interval, 1.73-46.13; P = .005]; SHIP study, p(trend) ≤ 0.001). Thus, preimmunization to PF4/bacteria complexes by prevalent infections, for example, periodontitis, likely explains the presence of natural anti-PF4/heparin Abs and the early occurrence of anti-PF4/H-IgG in HIT.
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