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Feix AS, Tabaie EZ, Singh AN, Wittenberg NJ, Wilson EH, Joachim A. An in-depth exploration of the multifaceted roles of EVs in the context of pathogenic single-cell microorganisms. Microbiol Mol Biol Rev 2024:e0003724. [PMID: 38869292 DOI: 10.1128/mmbr.00037-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024] Open
Abstract
SUMMARYExtracellular vesicles (EVs) have been recognized throughout scientific communities as potential vehicles of intercellular communication in both eukaryotes and prokaryotes, thereby influencing various physiological and pathological functions of both parent and recipient cells. This review provides an in-depth exploration of the multifaceted roles of EVs in the context of bacteria and protozoan parasite EVs, shedding light on their contributions to physiological processes and disease pathogenesis. These studies highlight EVs as a conserved mechanism of cellular communication, which may lead us to important breakthroughs in our understanding of infection, mechanisms of pathogenesis, and as indicators of disease. Furthermore, EVs are involved in host-microbe interactions, offering insights into the strategies employed by bacteria and protozoan parasites to modulate host responses, evade the immune system, and establish infections.
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Affiliation(s)
- Anna Sophia Feix
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Emily Z Tabaie
- Division of Biomedical Sciences, University of California, Riverside, California, USA
| | - Aarshi N Singh
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania, USA
| | | | - Emma H Wilson
- Division of Biomedical Sciences, University of California, Riverside, California, USA
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
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2
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Singh A, Nice JB, Wu M, Brown AC, Wittenberg NJ. Multivariate Analysis of Individual Bacterial Outer Membrane Vesicles Using Fluorescence Microscopy. CHEMICAL & BIOMEDICAL IMAGING 2024; 2:352-361. [PMID: 38817321 PMCID: PMC11134603 DOI: 10.1021/cbmi.4c00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/28/2024] [Accepted: 04/11/2024] [Indexed: 06/01/2024]
Abstract
Gram-negative bacteria produce outer membrane vesicles (OMVs) that play a critical role in cell-cell communication and virulence. OMVs have emerged as promising therapeutic agents for various biological applications such as vaccines and targeted drug delivery. However, the full potential of OMVs is currently constrained by inherent heterogeneities, such as size and cargo differences, and traditional ensemble assays are limited in their ability to reveal OMV heterogeneity. To overcome this issue, we devised an innovative approach enabling the identification of various characteristics of individual OMVs. This method, employing fluorescence microscopy, facilitates the detection of variations in size and surface markers. To demonstrate our method, we utilize the oral bacterium Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) which produces OMVs with a bimodal size distribution. As part of its virulence, A. actinomycetemcomitans secretes leukotoxin (LtxA) in two forms: soluble and surface associated with the OMVs. We observed a correlation between the size and toxin presence where larger OMVs were much more likely to possess LtxA compared to the smaller OMVs. In addition, we noted that, among the smallest OMVs (<100 nm diameter), the fractions that are toxin positive range from 0 to 30%, while the largest OMVs (>200 nm diameter) are between 70 and 100% toxin positive.
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Affiliation(s)
- Aarshi
N. Singh
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Justin B Nice
- Department
of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Meishan Wu
- Department
of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Angela C. Brown
- Department
of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Nathan J. Wittenberg
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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3
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Nice JB, Collins SM, Agro SMJ, Sinani A, Moros SD, Pasch LM, Brown AC. Heterogeneity of Size and Toxin Distribution in Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles. Toxins (Basel) 2024; 16:138. [PMID: 38535804 PMCID: PMC10974469 DOI: 10.3390/toxins16030138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/21/2024] [Accepted: 02/29/2024] [Indexed: 04/01/2024] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of A. actinomycetemcomitans most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs). We previously observed that the highly leukotoxic A. actinomycetemcomitans strain JP2 produces two populations of OMVs: a highly abundant population of small (<100 nm) OMVs and a less abundant population of large (>300 nm) OMVs. Here, we have developed a protocol to isolate the OMVs produced during each specific phase of growth and used this to demonstrate that small OMVs are produced throughout growth and lack LtxA, while large OMVs are produced only during the exponential phase and are enriched with LtxA. Our results indicate that surface-associated DNA drives the selective sorting of LtxA into large OMVs. This study provides valuable insights into the observed heterogeneity of A. actinomycetemcomitans vesicles and emphasizes the importance of understanding these variations in the context of bacterial pathogenesis.
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Affiliation(s)
- Justin B Nice
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Shannon M. Collins
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Samuel M. J. Agro
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Anxhela Sinani
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Spencer D. Moros
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Leah M. Pasch
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
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4
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Huang B, Liu C, Yang J, Xiang E, Ivanovski S, Han P. Saliva biofilm-derived outer membrane vesicles regulate biofilm formation and immune response of oral epithelial cells on titanium surfaces. Clin Oral Investig 2024; 28:75. [PMID: 38175302 DOI: 10.1007/s00784-023-05454-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024]
Abstract
OBJECTIVES While the significant roles of outer membrane vesicles (OMVs) from individual oral bacterial species in bacterial-host interactions are known, the involvement of saliva biofilm-derived OMVs in peri-implant disease pathogenesis remains unclear. This study aimed to investigate the effect of saliva biofilm-derived OMVs on regulating saliva biofilm formation and modulating the immune response of the epithelial cells on titanium surfaces. MATERIALS AND METHODS Saliva derived biofilms were cultured on tissue culture plates (TCP) for 4 days using pooled saliva from four healthy donors. OMVs secreted from the TCP bound biofilm (referred to as OMVs or healthy saliva biofilm OMVs) were enriched using the size-exclusion chromatography method. We then evaluated the effects of these OMVs on the viability, metabolic activity, and the presence of oral pathogens in saliva biofilm grown on titanium discs for 24 h and 72 h. Furthermore, the impact of OMVs on the mRNA expression and inflammatory cytokines [interleukin (IL)-6, IL-1α, and monocyte chemoattractant protein-1 (MCP-1)] in human oral epithelial cells (OKF6/TERT-2) was investigated using RT-qPCR and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS Healthy saliva biofilm OMVs improved the biomass and activity of saliva biofilm cultured on the titanium surfaces, with inhibited Porphyromonas gingivalis and Fusobacterium nucleatum, and enhanced Streptococcus mutans expression. Additionally, OMVs increased pro-inflammatory cytokine IL-6 mRNA and IL-6 cytokine expression in human oral epithelial cells. However, IL-1α and MCP-1 cytokines were inhibited 24-hour post-incubation with OMVs. CONCLUSION Healthy saliva biofilm derived OMVs regulate the activity and pathogen composition of biofilms formed on titanium, while modulating the secretion of pro-inflammation factors of oral epithelial cells grown on titanium surfaces. CLINICAL RELEVANCE Healthy saliva biofilm OMVs may regulate the early biofilm formation on abutment surfaces and modulate epithelial cell immune response, which may alter the peri-implant niche and participate in the pathogenesis of peri-implant disease.
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Affiliation(s)
- Baoxin Huang
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, People's Republic of China
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, People's Republic of China
- The University of Queensland, School of Dentistry, QLD, Brisbane, 4006, Australia
- The University of Queensland, School of Dentistry, Centre for Oral-Facial Regeneration, Rehabilitation and Reconstruction (COR3), Brisbane, Queensland, Australia
| | - Chun Liu
- The University of Queensland, School of Dentistry, QLD, Brisbane, 4006, Australia
- The University of Queensland, School of Dentistry, Centre for Oral-Facial Regeneration, Rehabilitation and Reconstruction (COR3), Brisbane, Queensland, Australia
| | - Jieting Yang
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, People's Republic of China
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Enmao Xiang
- The University of Queensland, School of Dentistry, QLD, Brisbane, 4006, Australia
- The University of Queensland, School of Dentistry, Centre for Oral-Facial Regeneration, Rehabilitation and Reconstruction (COR3), Brisbane, Queensland, Australia
| | - Sašo Ivanovski
- The University of Queensland, School of Dentistry, QLD, Brisbane, 4006, Australia.
- The University of Queensland, School of Dentistry, Centre for Oral-Facial Regeneration, Rehabilitation and Reconstruction (COR3), Brisbane, Queensland, Australia.
| | - Pingping Han
- The University of Queensland, School of Dentistry, QLD, Brisbane, 4006, Australia.
- The University of Queensland, School of Dentistry, Centre for Oral-Facial Regeneration, Rehabilitation and Reconstruction (COR3), Brisbane, Queensland, Australia.
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Warsi OM, Gedda L, Edwards K, Andersson DI. Vesicle-enriched secretomes alter bacterial competitive abilities and are drivers of evolution in microbial communities. FEMS Microbiol Ecol 2023; 99:fiad141. [PMID: 37884450 PMCID: PMC10653989 DOI: 10.1093/femsec/fiad141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023] Open
Abstract
Microbial membrane vesicles can carry compounds that inhibit bacterial growth, but how they impact the fitness of the vesicle-producing bacterial species and influence community dynamics remain unexplored questions. To address these questions, we examined the effect of vesicle-enriched secretomes (VESs) in different single-species and multi-species systems. Effects of VESs on single-species growth dynamics were determined for nine bacterial species belonging to four genera (Escherichia, Salmonella, Pseudomonas and Bacillus) in nutrient-rich and poor growth media. Results showed both species-specific and nutrient-dependent effects of the VESs on bacterial growth. The strongest antagonistic effects were observed for VES isolated from the natural isolates of E. coli, while those isolated from P. aeruginosa PA14 affected the highest number of species. We further demonstrated that these VESs altered the competitive abilities of the species involved in two-species (S. Typhimurium LT2 and S. arizonae) and three-species systems (E. coli, S. Typhimurium LT2 and B. subtilis). Finally, using experimental evolution we showed that different bacterial species could rapidly acquire mutations that abrogated the antagonistic effects of VESs. This study demonstrates how VESs can contribute in shaping microbial communities, both by increasing the competitive ability of a given bacterial species and as a driver of genetic adaptation.
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Affiliation(s)
- Omar M Warsi
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala 75123, Sweden
| | - Lars Gedda
- Department of Chemistry-Ångström, Uppsala University, Uppsala 75237, Sweden
| | - Katarina Edwards
- Department of Chemistry-Ångström, Uppsala University, Uppsala 75237, Sweden
| | - Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala 75123, Sweden
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6
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Li Y, Yang KD, Kong DC, Ye JF. Advances in phage display based nano immunosensors for cholera toxin. Front Immunol 2023; 14:1224397. [PMID: 37781379 PMCID: PMC10534012 DOI: 10.3389/fimmu.2023.1224397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/23/2023] [Indexed: 10/03/2023] Open
Abstract
Cholera, a persistent global public health concern, continues to cause outbreaks in approximately 30 countries and territories this year. The imperative to safeguard water sources and food from Vibrio cholerae, the causative pathogen, remains urgent. The bacterium is mainly disseminated via ingestion of contaminated water or food. Despite the plate method's gold standard status for detection, its time-consuming nature, taking several days to provide results, remains a challenge. The emergence of novel virulence serotypes raises public health concerns, potentially compromising existing detection methods. Hence, exploiting Vibrio cholerae toxin testing holds promise due to its inherent stability. Immunobiosensors, leveraging antibody specificity and sensitivity, present formidable tools for detecting diverse small molecules, encompassing drugs, hormones, toxins, and environmental pollutants. This review explores cholera toxin detection, highlighting phage display-based nano immunosensors' potential. Engineered bacteriophages exhibit exceptional cholera toxin affinity, through specific antibody fragments or mimotopes, enabling precise quantification. This innovative approach promises to reshape cholera toxin detection, offering an alternative to animal-derived methods. Harnessing engineered bacteriophages aligns with ethical detection and emphasizes sensitivity and accuracy, a pivotal stride in the evolution of detection strategies. This review primarily introduces recent advancements in phage display-based nano immunosensors for cholera toxin, encompassing technical aspects, current challenges, and future prospects.
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Affiliation(s)
- Yang Li
- General Surgery Center, First Hospital of Jilin University, Changchun, Jilin, China
- School of Nursing, Jilin University, Changchun, China
| | - Kai-di Yang
- School of Nursing, Jilin University, Changchun, China
| | - De-cai Kong
- General Surgery Center, First Hospital of Jilin University, Changchun, Jilin, China
| | - Jun-feng Ye
- General Surgery Center, First Hospital of Jilin University, Changchun, Jilin, China
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7
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Singh AN, Nice JB, Brown AC, Wittenberg NJ. Identifying size-dependent toxin sorting in bacterial outer membrane vesicles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539273. [PMID: 37205353 PMCID: PMC10187208 DOI: 10.1101/2023.05.03.539273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Gram-negative bacteria produce outer membrane vesicles (OMVs) that play a critical role in cell-cell communication and virulence. Despite being isolated from a single population of bacteria, OMVs can exhibit heterogeneous size and toxin content, which can be obscured by assays that measure ensemble properties. To address this issue, we utilize fluorescence imaging of individual OMVs to reveal size-dependent toxin sorting. Our results showed that the oral bacterium Aggregatibacter actinomycetemcomitans (A.a.) produces OMVs with a bimodal size distribution, where larger OMVs were much more likely to possess leukotoxin (LtxA). Among the smallest OMVs (< 100 nm diameter), the fraction that are toxin positive ranges from 0-30%, while the largest OMVs (> 200 nm diameter) are between 70-100% toxin positive. Our single OMV imaging method provides a non-invasive way to observe OMV surface heterogeneity at the nanoscale level and determine size-based heterogeneities without the need for OMV fraction separation.
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Affiliation(s)
- Aarshi N. Singh
- Department of Chemistry, Lehigh University, Bethlehem, PA, U.S.A
| | - Justin B Nice
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, U.S.A
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, U.S.A
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8
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Composition and functions of bacterial membrane vesicles. Nat Rev Microbiol 2023:10.1038/s41579-023-00875-5. [PMID: 36932221 DOI: 10.1038/s41579-023-00875-5] [Citation(s) in RCA: 87] [Impact Index Per Article: 87.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2023] [Indexed: 03/19/2023]
Abstract
Extracellular vesicles are produced by species across all domains of life, suggesting that vesiculation represents a fundamental principle of living matter. In Gram-negative bacteria, membrane vesicles (MVs) can originate either from blebs of the outer membrane or from endolysin-triggered explosive cell lysis, which is often induced by genotoxic stress. Although less is known about the mechanisms of vesiculation in Gram-positive and Gram-neutral bacteria, recent research has shown that both lysis and blebbing mechanisms also exist in these organisms. Evidence has accumulated over the past years that different biogenesis routes lead to distinct types of MV with varied structure and composition. In this Review, we discuss the different types of MV and their potential cargo packaging mechanisms. We summarize current knowledge regarding how MV composition determines their various functions including support of bacterial growth via the disposal of waste material, nutrient scavenging, export of bioactive molecules, DNA transfer, neutralization of phages, antibiotics and bactericidal functions, delivery of virulence factors and toxins to host cells and inflammatory and immunomodulatory effects. We also discuss the advantages of MV-mediated secretion compared with classic bacterial secretion systems and we introduce the concept of quantal secretion.
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Fu Y, Maaβ S, Cavallo FM, de Jong A, Raangs E, Westra J, Buist G, Becher D, van Dijl JM. Differential Virulence of Aggregatibacter actinomycetemcomitans Serotypes Explained by Exoproteome Heterogeneity. Microbiol Spectr 2023; 11:e0329822. [PMID: 36541765 PMCID: PMC9927298 DOI: 10.1128/spectrum.03298-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with periodontitis and nonoral diseases like rheumatoid arthritis and Alzheimer´s disease. Aa isolates with the serotypes a, b, and c are globally most prevalent. Importantly, isolates displaying these serotypes have different clinical presentations. While serotype b isolates are predominant in severe periodontitis, serotypes a and c are generally encountered in mild periodontitis or healthy individuals. It is currently unknown how these differences are reflected in the overall secretion of virulence factors. Therefore, this study was aimed at a comparative analysis of exoproteomes from different clinical Aa isolates with serotypes a, b, or c by mass spectrometry, and a subsequent correlation of the recorded exoproteome profiles with virulence. Overall, we identified 425 extracellular proteins. Significant differences in the exoproteome composition of isolates with different serotypes were observed in terms of protein identification and abundance. In particular, serotype a isolates presented more extracellular proteins than serotype b or c isolates. These differences are mirrored in their virulence in infection models based on human salivary gland epithelial cells and neutrophils. Remarkably, serotype a isolates displayed stronger adhesive capabilities and induced more lysis of epithelial cells and neutrophils than serotype b or c isolates. Conversely, serotype c isolates showed relatively low leukotoxicity, while provoking NETosis to similar extents as serotype a and b isolates. Altogether, we conclude that the differential virulence presentation by Aa isolates with the dominant serotypes a, b, or c can be explained by their exoproteome heterogeneity. IMPORTANCE Periodontitis is an inflammatory disease that causes progressive destruction of alveolar bone and supporting tissues around the teeth, ultimately resulting in tooth loss. The bacterium Aggregatibacter actinomycetemcomitans (Aa) is a prevalent causative agent of periodontitis, but this oral pathogen is also associated with serious extraoral diseases like rheumatoid arthritis and Alzheimer's disease. Clinical Aa isolates are usually distinguished by serotyping, because of known serotype-specific differences in virulence. Aa with serotype b is associated with aggressive forms of periodontitis, while isolates with serotypes a or c are usually encountered in cases of mild periodontitis or healthy individuals. The molecular basis for these differences in virulence was so far unknown. In the present study, we pinpoint serotype-specific differences in virulence factor production by clinical Aa isolates. We consider these findings important, because they provide new leads for future preventive or therapeutic approaches to fight periodontitis and associated morbidities.
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Affiliation(s)
- Yanyan Fu
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Sandra Maaβ
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Francis M. Cavallo
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Anne de Jong
- University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Department of Molecular Genetics, Groningen, the Netherlands
| | - Erwin Raangs
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Johanna Westra
- University of Groningen, University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen, the Netherlands
| | - Girbe Buist
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Dörte Becher
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Jan Maarten van Dijl
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
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Kong C, Zhang H, Li L, Liu Z. Effects of green tea extract epigallocatechin-3-gallate (EGCG) on oral disease-associated microbes: a review. J Oral Microbiol 2022; 14:2131117. [PMID: 36212989 PMCID: PMC9542882 DOI: 10.1080/20002297.2022.2131117] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
For thousands of years, caries, periodontitis and mucosal diseases, which are closely related to oral microorganisms, have always affected human health and quality of life. These complex microbiota present in different parts of the mouth can cause chronic infections in the oral cavity under certain conditions, some of which can also lead to acute and systemic diseases. With the mutation of related microorganisms and the continuous emergence of drug-resistant strains, in order to prevent and treat related diseases, in addition to the innovation of diagnosis and treatment technology, the development of new antimicrobial drugs is also important. Catechins are polyphenolic compounds in green tea, some of which are reported to provide health benefits for a variety of diseases. Studies have shown that epigallocatechin-3-gallate (EGCG) is the most abundant and effective active ingredient in green tea catechins, which acts against a variety of gram-positive and negative bacteria, as well as some fungi and viruses. This review aims to summarize the research progress on the activity of EGCG against common oral disease-associated organisms and discuss the mechanisms of these actions, hoping to provide new medication strategies for the prevention and treatment of oral infectious diseases, the future research of EGCG and its translation into clinical practice are also discussed.
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Affiliation(s)
- Chen Kong
- Hospital of Stomatology, Jilin University, Changchun, Jilin, China
| | - Huili Zhang
- Hospital of Stomatology, Jilin University, Changchun, Jilin, China
| | - Lingfeng Li
- Hospital of Stomatology, Jilin University, Changchun, Jilin, China
| | - Zhihui Liu
- Hospital of Stomatology, Jilin University, Changchun, Jilin, China
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11
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Ma F, Luo S, Lu C, Jiang X, Chen K, Deng J, Ma S, Li Z. The role of Nrf2 in periodontal disease by regulating lipid peroxidation, inflammation and apoptosis. Front Endocrinol (Lausanne) 2022; 13:963451. [PMID: 36482997 PMCID: PMC9723463 DOI: 10.3389/fendo.2022.963451] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/02/2022] [Indexed: 11/23/2022] Open
Abstract
Nuclear factor E2-related factor 2(Nrf2) is a transcription factor that mainly regulates oxidative stress in the body. It initiates the expression of several downstream antioxidants, anti-inflammatory proteins and detoxification enzymes through the Kelch-like ECH-associating protein 1 (Keap1) -nuclear factor E2-related factor 2(Nrf2) -antioxidant response element (ARE) signaling pathway. Its anti-apoptosis, anti-oxidative stress and anti-inflammatory effects have gradually become the focus of periodontal disease research in recent years. In this paper, the structure and function of Nrf2 pathway and its mechanism of action in the treatment of periodontitis in recent years were analyzed and summarized, so as to further clarify the relationship between Nrf2 pathway and oxidative stress in the occurrence and development of periodontitis, and to provide ideas for the development of new treatment drugs targeting Nrf2 pathway.
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Affiliation(s)
- Fengyu Ma
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- School of Stomatology, Jinan University, Guangzhou, Guangdong, China
| | - Shangdie Luo
- Department of Orthodontics, Huizhou Stomatological Hospital, Huizhou, Guangdong, China
| | - Chunting Lu
- Science and Education Office, The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China
| | - Xinrong Jiang
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- School of Stomatology, Jinan University, Guangzhou, Guangdong, China
| | - Kexiao Chen
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- School of Stomatology, Jinan University, Guangzhou, Guangdong, China
| | - Jianwen Deng
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- School of Stomatology, Jinan University, Guangzhou, Guangdong, China
| | - Shuyuan Ma
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Zejian Li
- Department of Stomatology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- School of Stomatology, Jinan University, Guangzhou, Guangdong, China
- Chaoshan Hospital, The First Affiliated Hospital of Jinan University, Chaozhou, Guangdong, China
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12
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Yu W, Li S, Zhang G, Xu HHK, Zhang K, Bai Y. New frontiers of oral sciences: Focus on the source and biomedical application of extracellular vesicles. Front Bioeng Biotechnol 2022; 10:1023700. [PMID: 36338125 PMCID: PMC9627311 DOI: 10.3389/fbioe.2022.1023700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 10/04/2022] [Indexed: 12/05/2022] Open
Abstract
Extracellular vesicles (EVs) are a class of nanoparticles that are derived from almost any type of cell in the organism tested thus far and are present in all body fluids. With the capacity to transfer "functional cargo and biological information" to regulate local and distant intercellular communication, EVs have developed into an attractive focus of research for various physiological and pathological conditions. The oral cavity is a special organ of the human body. It includes multiple types of tissue, and it is also the beginning of the digestive tract. Moreover, the oral cavity harbors thousands of bacteria. The importance and particularity of oral function indicate that EVs derived from oral cavity are quite complex but promising for further research. This review will discuss the extensive source of EVs in the oral cavity, including both cell sources and cell-independent sources. Besides, accumulating evidence supports extensive biomedical applications of extracellular vesicles in oral tissue regeneration and development, diagnosis and treatment of head and neck tumors, diagnosis and therapy of systemic disease, drug delivery, and horizontal gene transfer (HGT). The immune cell source, odontoblasts and ameloblasts sources, diet source and the application of EVs in tooth development and HGT were reviewed for the first time. In conclusion, we concentrate on the extensive source and potential applications offered by these nanovesicles in oral science.
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Affiliation(s)
- Wenting Yu
- Department of Orthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Shengnan Li
- Department of Orthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Guohao Zhang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology and National Center of Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Hockin H. K. Xu
- Biomaterials and Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, United States
- Center for Stem Cell Biology and Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Ke Zhang
- Department of Orthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Yuxing Bai
- Department of Orthodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
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13
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Ozuna H, Snider I, Belibasakis GN, Oscarsson J, Johansson A, Uriarte SM. Aggregatibacter actinomycetemcomitans and Filifactor alocis: Two exotoxin-producing oral pathogens. FRONTIERS IN ORAL HEALTH 2022; 3:981343. [PMID: 36046121 PMCID: PMC9420871 DOI: 10.3389/froh.2022.981343] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/27/2022] [Indexed: 12/22/2022] Open
Abstract
Periodontitis is a dysbiotic disease caused by the interplay between the microbial ecosystem present in the disease with the dysregulated host immune response. The disease-associated microbial community is formed by the presence of established oral pathogens like Aggregatibacter actinomycetemcomitans as well as by newly dominant species like Filifactor alocis. These two oral pathogens prevail and grow within the periodontal pocket which highlights their ability to evade the host immune response. This review focuses on the virulence factors and potential pathogenicity of both oral pathogens in periodontitis, accentuating the recent description of F. alocis virulence factors, including the presence of an exotoxin, and comparing them with the defined factors associated with A. actinomycetemcomitans. In the disease setting, possible synergistic and/or mutualistic interactions among both oral pathogens might contribute to disease progression.
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Affiliation(s)
- Hazel Ozuna
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Ian Snider
- Department of Biology, School of Arts and Sciences, University of Louisville, Louisville, KY, United States
| | | | - Jan Oscarsson
- Department of Odontology, Umeå University, Umeå, Sweden
| | | | - Silvia M. Uriarte
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States,*Correspondence: Silvia M. Uriarte
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14
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Connections between Exoproteome Heterogeneity and Virulence in the Oral Pathogen Aggregatibacter actinomycetemcomitans. mSystems 2022; 7:e0025422. [PMID: 35695491 PMCID: PMC9239275 DOI: 10.1128/msystems.00254-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterial pathogen associated with severe periodontitis and nonoral diseases. Clinical isolates of A. actinomycetemcomitans display a rough (R) colony phenotype with strong adherent properties. Upon prolonged culturing, nonadherent strains with a smooth (S) colony phenotype emerge. To date, most virulence studies on A. actinomycetemcomitans have been performed with S strains of A. actinomycetemcomitans, whereas the virulence of clinical R isolates has received relatively little attention. Since the extracellular proteome is the main bacterial reservoir of virulence factors, the present study was aimed at a comparative analysis of this subproteome fraction for a collection of R isolates and derivative S strains, in order to link particular proteins to the virulence of A. actinomycetemcomitans with serotype b. To assess the bacterial virulence, we applied different infection models based on larvae of the greater wax moth Galleria mellonella, a human salivary gland-derived epithelial cell line, and freshly isolated neutrophils from healthy human volunteers. A total number of 351 extracellular A. actinomycetemcomitans proteins was identified by mass spectrometry, with the S strains consistently showing more extracellular proteins than their parental R isolates. A total of 50 known extracellular virulence factors was identified, of which 15 were expressed by all investigated bacteria. Importantly, the comparison of differences in exoproteome composition and virulence highlights critical roles of 10 extracellular proteins in the different infection models. Together, our findings provide novel clues for understanding the virulence of A. actinomycetemcomitans and for development of potential preventive or therapeutic avenues to neutralize this important oral pathogen. IMPORTANCE Periodontitis is one of the most common inflammatory diseases worldwide, causing high morbidity and decreasing the quality of life of millions of people. The bacterial pathogen Aggregatibacter actinomycetemcomitans is strongly associated with aggressive forms of periodontitis. Moreover, it has been implicated in serious nonoral infections, including endocarditis and brain abscesses. Therefore, it is important to investigate how A. actinomycetemcomitans can cause disease. In the present study, we applied a mass spectrometry approach to make an inventory of the virulence factors secreted by different clinical A. actinomycetemcomitans isolates and derivative strains that emerged upon culturing. We subsequently correlated the secreted virulence factors to the pathogenicity of the investigated bacteria in different infection models. The results show that a limited number of extracellular virulence factors of A. actinomycetemcomitans have central roles in pathogenesis, indicating that they could be druggable targets to prevent or treat oral disease.
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15
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Ozdemir NK, Cline JP, Sakizadeh J, Collins SM, Brown AC, McIntosh S, Kiely CJ, Snyder MA. Sequential, low-temperature aqueous synthesis of Ag-In-S/Zn quantum dots via staged cation exchange under biomineralization conditions. J Mater Chem B 2022; 10:4529-4545. [PMID: 35608268 DOI: 10.1039/d2tb00682k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of high quality, non-toxic (i.e., heavy-metal-free), and functional quantum dots (QDs) via 'green' and scalable synthesis routes is critical for realizing truly sustainable QD-based solutions to diverse technological challenges. Herein, we demonstrate the low-temperature all-aqueous-phase synthesis of silver indium sulfide/zinc (AIS/Zn) QDs with a process initiated by the biomineralization of highly crystalline indium sulfide nanocrystals, and followed by the sequential staging of Ag+ cation exchange and Zn2+ addition directly within the biomineralization media without any intermediate product purification. Therein, we exploit solution phase cation concentration, the duration of incubation in the presence of In2S3 precursor nanocrystals, and the subsequent addition of Zn2+ as facile handles under biomineralization conditions for controlling QD composition, tuning optical properties, and improving the photoluminescence quantum yield of the AIS/Zn product. We demonstrate how engineering biomineralization for the synthesis of intrinsically hydrophilic and thus readily functionalizable AIS/Zn QDs with a quantum yield of 18% offers a 'green' and non-toxic materials platform for targeted bioimaging in sensitive cellular systems. Ultimately, the decoupling of synthetic steps helps unravel the complexities of ion exchange-based synthesis within the biomineralization platform, enabling its adaptation for the sustainable synthesis of 'green', compositionally diverse QDs.
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Affiliation(s)
- Nur Koncuy Ozdemir
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Joseph P Cline
- Dept. of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - John Sakizadeh
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Shannon M Collins
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Angela C Brown
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Steven McIntosh
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Christopher J Kiely
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA. .,Dept. of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Mark A Snyder
- Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
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16
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Zou C, Zhang Y, Liu H, Wu Y, Zhou X. Extracellular Vesicles: Recent Insights Into the Interaction Between Host and Pathogenic Bacteria. Front Immunol 2022; 13:840550. [PMID: 35693784 PMCID: PMC9174424 DOI: 10.3389/fimmu.2022.840550] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 04/27/2022] [Indexed: 02/05/2023] Open
Abstract
Extracellular vesicles (EVs) are nanosized lipid particles released by virtually every living cell. EVs carry bioactive molecules, shuttle from cells to cells and transduce signals, regulating cell growth and metabolism. Pathogenic bacteria can cause serious infections via a wide range of strategies, and host immune systems also develop extremely complex adaptations to counteract bacterial infections. As notable carriers, EVs take part in the interaction between the host and bacteria in several approaches. For host cells, several strategies have been developed to resist bacteria via EVs, including expelling damaged membranes and bacteria, neutralizing toxins, triggering innate immune responses and provoking adaptive immune responses in nearly the whole body. For bacteria, EVs function as vehicles to deliver toxins and contribute to immune escape. Due to their crucial functions, EVs have great application potential in vaccines, diagnosis and treatments. In the present review, we highlight the most recent advances, application potential and remaining challenges in understanding EVs in the interaction between the host and bacteria.
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Affiliation(s)
- Chaoyu Zou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
- Department of Hematology and Hematology Research Laboratory, West China Hospital, Sichuan University, Chengdu, China
| | - Yige Zhang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Huan Liu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Yu Wu
- Department of Hematology and Hematology Research Laboratory, West China Hospital, Sichuan University, Chengdu, China
| | - Xikun Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
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17
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Liang L, Yang C, Liu L, Mai G, Li H, Wu L, Jin M, Chen Y. Commensal bacteria-derived extracellular vesicles suppress ulcerative colitis through regulating the macrophages polarization and remodeling the gut microbiota. Microb Cell Fact 2022; 21:88. [PMID: 35578339 PMCID: PMC9109417 DOI: 10.1186/s12934-022-01812-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/03/2022] [Indexed: 12/13/2022] Open
Abstract
Background The extracellular vesicles (EVs) traffic constitutes an essential pathway of cellular communication. And the molecules in EVs produced by procaryotes help in maintaining homeostasis, addressing microbial imbalance and infections, and regulating the immune system. Despite the fact that Clostridium butyricum (C. butyricum) is commonly used for treating ulcerative colitis (UC), the potential role of C. butyricum-secreted EVs in commensals-host crosstalk remains unclear. Results Here, we performed flow cytometry, western blot, immunohistochemistry and 16S rRNA analysis to explore the role of C. butyricum-derived EVs on macrophage polarization and gut microbiota composition in a dextran sulfate sodium (DSS)-induced UC mouse model. The antibiotic cocktail-induced microbiome depletion and faecal transplantations were used to further investigate the mechanisms by which EVs regulate macrophage balance. Our findings showed that C. butyricum-derived EVs improved the remission of murine colitis and polarized the transformation of macrophages to the M2 type. Furthermore, C. butyricum-derived EVs restored gut dysbiosis and altered the relative abundance of Helicobacter, Escherichia-Shigella, Lactobacillus, Akkermansia and Bacteroides, which, in turn, faecal transplantations from EVs-treated mice relieved the symptoms of UC and improved the impact of EVs on the reprogramming of the M2 macrophages. Conclusion C. butyricum-derived EVs could protect against DSS-induced colitis by regulating the repolarization of M2 macrophages and remodelling the composition of gut microbiota, suggesting the potential efficacy of EVs from commensal and probiotic Clostridium species against UC. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01812-6.
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18
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Filipi K, Rahman WU, Osickova A, Osicka R. Kingella kingae RtxA Cytotoxin in the Context of Other RTX Toxins. Microorganisms 2022; 10:microorganisms10030518. [PMID: 35336094 PMCID: PMC8953716 DOI: 10.3390/microorganisms10030518] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/04/2022] Open
Abstract
The Gram-negative bacterium Kingella kingae is part of the commensal oropharyngeal flora of young children. As detection methods have improved, K. kingae has been increasingly recognized as an emerging invasive pathogen that frequently causes skeletal system infections, bacteremia, and severe forms of infective endocarditis. K. kingae secretes an RtxA cytotoxin, which is involved in the development of clinical infection and belongs to an ever-growing family of cytolytic RTX (Repeats in ToXin) toxins secreted by Gram-negative pathogens. All RTX cytolysins share several characteristic structural features: (i) a hydrophobic pore-forming domain in the N-terminal part of the molecule; (ii) an acylated segment where the activation of the inactive protoxin to the toxin occurs by a co-expressed toxin-activating acyltransferase; (iii) a typical calcium-binding RTX domain in the C-terminal portion of the molecule with the characteristic glycine- and aspartate-rich nonapeptide repeats; and (iv) a C-proximal secretion signal recognized by the type I secretion system. RTX toxins, including RtxA from K. kingae, have been shown to act as highly efficient ‘contact weapons’ that penetrate and permeabilize host cell membranes and thus contribute to the pathogenesis of bacterial infections. RtxA was discovered relatively recently and the knowledge of its biological role remains limited. This review describes the structure and function of RtxA in the context of the most studied RTX toxins, the knowledge of which may contribute to a better understanding of the action of RtxA in the pathogenesis of K. kingae infections.
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19
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Aggregatibacter actinomycetemcomitans Leukotoxin Activates the NLRP3 Inflammasome and Cell-to-Cell Communication. Pathogens 2022; 11:pathogens11020159. [PMID: 35215102 PMCID: PMC8877716 DOI: 10.3390/pathogens11020159] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/04/2023] Open
Abstract
Carriers of highly leukotoxic genotypes of Aggregatibacter actinomycetemcomitans are at high risk for rapid degradation of tooth-supporting tissues. The leukotoxin (LtxA) expressed by this bacterium induces a rapid pro-inflammatory response in leukocytes that results in cell death. The aim of the present study was to increase the understanding of LtxA-induced leukocyte activation mechanisms and of possible associated osteoclast differentiation. The effect of LtxA on activation of the inflammasome complex was studied in THP-1 wild type and in NLRP3- and ASC knockout cells. Cell-to-cell communication was assessed by fluorescent parachute assays, and THP-1 differentiation into osteoclast-like cells was investigated microscopically. The results showed that LtxA induced inflammatory cell death, which involved activation of the NLRP3 inflammasome and gap junction cell-to-cell communication. THP-1 cells treated with lipopolysaccharide (LPS) and LtxA together differentiated into an osteoclast-like phenotype. Here, LPS prevented LtxA-mediated cell death but failed to induce osteoclast differentiation on its own. However, pit formation was not significantly enhanced by LtxA. We conclude that A. actinomycetemcomitans leukotoxicity mediates activation of the NLRP3 inflammasome and cell-to-cell communication in the induced pro-inflammatory cell death. In addition, LtxA stimulated differentiation towards osteoclasts-like cells in LPS-treated THP-1 cells.
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20
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Liu L, Liang L, Yang C, Zhou Y, Chen Y. Extracellular vesicles of Fusobacterium nucleatum compromise intestinal barrier through targeting RIPK1-mediated cell death pathway. Gut Microbes 2022; 13:1-20. [PMID: 33769187 PMCID: PMC8007154 DOI: 10.1080/19490976.2021.1902718] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Microbial factors that mediate microbes-host interaction in ulcerative colitis (UC), a chronic disease seriously affecting human health, are not fully known. The emerging oncobacterium Fusobacterium nucleatum (Fn) secretes extracellular vesicles carrying several types of harmful molecules in the intestine which can alter microbes-host interaction, especially the epithelial homeostasis in UC. However, the mechanism is not yet clear. Previously, we isolated EVs by the ultracentrifugation of Fn culture media and characterized them as the potent inducer of pro-inflammatory cytokines. Here, we examined the mechanism in detail. We found that in macrophage/Caco-2 co-cultures, FnEVs significantly promoted epithelial barrier loss and oxidative stress damage, which are related to epithelial necroptosis caused by the activation of receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein kinase 3 (RIPK3). Furthermore, FnEVs promoted the migration of RIPK1 and RIPK3 into necrosome in Caco2 cells. Notably, these effects were reversed by TNF-α neutralizing antibody or Necrostatin-1 (Nec-1), a RIPK1 inhibitor. This suggested that FADD-RIPK1-caspase-3 signaling is involved in the process. Moreover, the observed effects were verified in the murine colitis model treated with FnEVs or by adoptive transfer of FnEVs-trained macrophages. In conclusion, we propose that RIPK1-mediated epithelial cell death promotes FnEVs-induced gut barrier disruption in UC and the findings can be used as the basis to further investigate this disease.
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Affiliation(s)
- Le Liu
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Liping Liang
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chenghai Yang
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Youlian Zhou
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ye Chen
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China,CONTACT Ye Chen Department of Gastroenterology,State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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21
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Cawley JL, Blauch ME, Collins SM, Nice JB, Xie Q, Jordan LR, Brown AC, Wittenberg NJ. Nanoarrays of Individual Liposomes and Bacterial Outer Membrane Vesicles by Liftoff Nanocontact Printing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2103338. [PMID: 34655160 PMCID: PMC8678320 DOI: 10.1002/smll.202103338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Analytical characterization of small biological particles, such as extracellular vesicles (EVs), is complicated by their extreme heterogeneity in size, lipid, membrane protein, and cargo composition. Analysis of individual particles is essential for illuminating particle property distributions that are obscured by ensemble measurements. To enable high-throughput analysis of individual particles, liftoff nanocontact printing (LNCP) is used to define hexagonal antibody and toxin arrays that have a 425 nm dot size, on average, and 700 nm periodicity. The LNCP process is rapid, simple, and does not require access to specialized nanofabrication tools. These densely packed, highly ordered arrays are used to capture liposomes and bacterial outer membrane vesicles on the basis of their surface biomarkers, with a maximum of one particle per array dot, resulting in densely packed arrays of particles. Despite the high particle density, the underlying antibody or toxin array ensured that neighboring individual particles are optically resolvable. Provided target particle biomarkers and suitable capture molecules are identified, this approach can be used to generate high density arrays of a wide variety of small biological particles, including other types of EVs like exosomes.
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Affiliation(s)
- Jennie L Cawley
- Department of Chemistry, Lehigh University, 6 E Packer Ave, Bethlehem, PA, 18015, USA
| | - Megan E Blauch
- Department of Chemistry, Lehigh University, 6 E Packer Ave, Bethlehem, PA, 18015, USA
| | - Shannon M Collins
- Department of Chemical and Biomolecular Engineering, Lehigh University, 111 Research Drive, Bethlehem, PA, 18015, USA
| | - Justin B Nice
- Department of Chemical and Biomolecular Engineering, Lehigh University, 111 Research Drive, Bethlehem, PA, 18015, USA
| | - Qing Xie
- Department of Chemistry, Lehigh University, 6 E Packer Ave, Bethlehem, PA, 18015, USA
| | - Luke R Jordan
- Department of Chemistry, Lehigh University, 6 E Packer Ave, Bethlehem, PA, 18015, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, 111 Research Drive, Bethlehem, PA, 18015, USA
| | - Nathan J Wittenberg
- Department of Chemistry, Lehigh University, 6 E Packer Ave, Bethlehem, PA, 18015, USA
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22
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Kim HY, Song M, Gho YS, Kim H, Choi B. Extracellular vesicles derived from the periodontal pathogen Filifactor alocis induce systemic bone loss through Toll-like receptor 2. J Extracell Vesicles 2021; 10:e12157. [PMID: 34648247 PMCID: PMC8516034 DOI: 10.1002/jev2.12157] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/17/2021] [Accepted: 09/27/2021] [Indexed: 01/31/2023] Open
Abstract
Periodontitis is an inflammatory disease induced by local infection in tooth-supporting tissue. Periodontitis is associated with systemic bone diseases, but little is known about the mechanism of the causal effect of periodontitis on systemic bone resorption. Bacteria-derived extracellular vesicles (EVs) act as natural carriers of virulence factors that are responsible for systemic inflammation. In this study, we investigated the role of EVs derived from Filifactor alocis, a Gram-positive, anaerobic periodontal pathogen, in systemic bone loss and osteoclast differentiation. F. alocis EVs accumulated in the long bones of mice after intraperitoneal administration. These EVs induced proinflammatory cytokines, osteoclastogenesis, and bone resorption via Toll-like receptor 2 (TLR2). The phase separation of F. alocis EVs showed that amphiphilic molecules were responsible for the induced bone resorption and osteoclastogenesis. The osteoclastogenic effects of F. alocis EVs were reduced by lipoprotein lipase. Proteomic analysis of the amphiphilic molecules identified seven lipoproteins. Our results indicate that lipoprotein-like molecules in F. alocis EVs may contribute to systemic bone loss via TLR2.
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Affiliation(s)
- Hyun Young Kim
- Department of Oral Microbiology and ImmunologySchool of Dentistry, Seoul National UniversitySeoulRepublic of Korea
| | - Min‐Kyoung Song
- Department of Cell and Developmental BiologySchool of Dentistry, Seoul National UniversitySeoulRepublic of Korea
- Department of Internal MedicineSeoul National University HospitalSeoulRepublic of Korea
| | - Yong Song Gho
- Department of Life SciencesPohang University of Science and Technology (POSTECH)PohangRepublic of Korea
| | - Hong‐Hee Kim
- Department of Cell and Developmental BiologySchool of Dentistry, Seoul National UniversitySeoulRepublic of Korea
- Dental Research InstituteSeoul National UniversitySeoulRepublic of Korea
| | - Bong‐Kyu Choi
- Department of Oral Microbiology and ImmunologySchool of Dentistry, Seoul National UniversitySeoulRepublic of Korea
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23
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Collins SM, Brown AC. Bacterial Outer Membrane Vesicles as Antibiotic Delivery Vehicles. Front Immunol 2021; 12:733064. [PMID: 34616401 PMCID: PMC8488215 DOI: 10.3389/fimmu.2021.733064] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/31/2021] [Indexed: 01/04/2023] Open
Abstract
Bacterial outer membrane vesicles (OMVs) are nanometer-scale, spherical vehicles released by Gram-negative bacteria into their surroundings throughout growth. These OMVs have been demonstrated to play key roles in pathogenesis by delivering certain biomolecules to host cells, including toxins and other virulence factors. In addition, this biomolecular delivery function enables OMVs to facilitate intra-bacterial communication processes, such as quorum sensing and horizontal gene transfer. The unique ability of OMVs to deliver large biomolecules across the complex Gram-negative cell envelope has inspired the use of OMVs as antibiotic delivery vehicles to overcome transport limitations. In this review, we describe the advantages, applications, and biotechnological challenges of using OMVs as antibiotic delivery vehicles, studying both natural and engineered antibiotic applications of OMVs. We argue that OMVs hold great promise as antibiotic delivery vehicles, an urgently needed application to combat the growing threat of antibiotic resistance.
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Affiliation(s)
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, United States
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24
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Applications of Catechins in the Treatment of Bacterial Infections. Pathogens 2021; 10:pathogens10050546. [PMID: 34062722 PMCID: PMC8147231 DOI: 10.3390/pathogens10050546] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 01/08/2023] Open
Abstract
Tea is the second most commonly consumed beverage worldwide. Along with its aromatic and delicate flavors that make it an enjoyable beverage, studies report numerous health advantages in tea consumption, including applications in antimicrobial therapy. The antimicrobial properties of tea are related to catechin and its derivatives, which are natural flavonoids that are abundant in tea. Increasing evidence from in vitro studies demonstrated antimicrobial effects of catechins on both gram-positive and gram-negative bacteria, and proposed direct and indirect therapeutic mechanisms. Additionally, catechins were reported to be effective anti-virulence agents. Furthermore, a number of studies presented evidence that catechins display synergistic effects with certain antibiotics, thus potentiating the activity of antibiotics in resistant bacteria. Despite their numerous beneficial properties, catechins face many challenges in their development as therapeutic agents, including poor absorption, low bioavailability, and rapid degradation. The introduction of nanobiotechnology provides target-based and stable delivery, which enhances catechin bioavailability and optimizes drug efficacy. As further research continues to focus on overcoming the unresolved challenges, catechins are likely to see additional promising applications in our continual fight against bacterial infections.
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25
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Ma L, Cao Z. Membrane vesicles from periodontal pathogens and their potential roles in periodontal disease and systemic illnesses. J Periodontal Res 2021; 56:646-655. [PMID: 33826135 DOI: 10.1111/jre.12884] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 02/18/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022]
Abstract
Periodontium is an ordered ecological system where a dynamic equilibrium exists between oral microorganisms and the host defense system, and periodontal disease occurs whenever the balance is broken. Periodontal pathogens mainly include gram-negative anaerobic bacteria and emerging gram-positive microbes, which have a large variety of virulence factors and influence disease initiation and progression. Recently, different types of bacterial membrane vesicles (MVs), formed by bubbling of membrane materials from living cells or in conditions of endolysin-triggered cell death, have gained interests as a novel virulence factor for periodontopathogens. MVs load multiple sorted cargo molecules, such as proteins, lipids, and genetic materials, and actively participate in toxin transport, signal delivery, and periodontal disease pathogenesis. Since periodontitis is recognized as a risk factor for many systemic diseases, periodontal MVs could work as a bridge for periodontal diseases and systemic illnesses. Furthermore, MVs with unique nature and advantages are promising candidates as vaccines and drug delivery vehicles. In this review, we provided an overview of different types and compositions of periodontal MVs, described their involvements in the pathogenesis of periodontitis and several general diseases, and discussed potential applications of periodontal MVs in vaccination and drug delivery.
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Affiliation(s)
- Li Ma
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST KLOS) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBME), School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Zhengguo Cao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST KLOS) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBME), School & Hospital of Stomatology, Wuhan University, Wuhan, China.,Department of Periodontology, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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Chang EH, Brown AC. Epigallocatechin gallate alters leukotoxin secretion and Aggregatibacter actinomycetemcomitans virulence. J Pharm Pharmacol 2021; 73:505-514. [PMID: 33793838 DOI: 10.1093/jpp/rgaa051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES We and others have previously shown that epigallocatechin gallate (EGCg) inhibits the activity of an important virulence factor, leukotoxin (LtxA), produced by the oral bacterium Aggregatibacter actinomycetemcomitans, suggesting the potential use of this molecule as an anti-virulence strategy to treat periodontal infections. Here, we sought to better understand the effects of EGCg on toxin secretion and A. actinomycetemcomitans pathogenicity in a co-culture model. METHODS We used a quantitative immunoblot assay to determine the concentrations of LtxA in the bacterial supernatant and on the bacterial cell surface. Using a co-culture model, consisting of A. actinomycetemcomitans and THP-1 cells, we studied the impact of EGCg-mediated changes in LtxA secretion on the toxicity of A. actinomycetemcomitans. KEY FINDINGS EGCg increased production of LtxA and changed the localization of secreted LtxA from the supernatant to the surface of the bacterial cells. In the co-culture model, a single low dose of EGCg did not protect host THP-1 cells from A. actinomycetemcomitans-mediated cytotoxicity, but a multiple dosing strategy had improved effects. CONCLUSIONS Together, these results demonstrate that EGCg has important, but complicated, effects on toxin secretion and activity; new dosing strategies and comprehensive model systems may be required to properly develop these anti-virulence activities.
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Affiliation(s)
- En Hyung Chang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
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27
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Leukotoxins. Toxins (Basel) 2020; 12:toxins12040231. [PMID: 32272577 PMCID: PMC7232309 DOI: 10.3390/toxins12040231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 12/04/2022] Open
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Krueger E, Brown AC. Aggregatibacter actinomycetemcomitans leukotoxin: From mechanism to targeted anti-toxin therapeutics. Mol Oral Microbiol 2020; 35:85-105. [PMID: 32061022 DOI: 10.1111/omi.12284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/13/2022]
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis, as well as other systemic diseases. This organism produces a number of virulence factors, all of which provide some advantage to the bacterium. Several studies have demonstrated that clinical isolates from diseased patients, particularly those of African descent, frequently belong to specific clones of A. actinomycetemcomitans that produce significantly higher amounts of a protein exotoxin belonging to the repeats-in-toxin (RTX) family, leukotoxin (LtxA), whereas isolates from healthy patients harbor minimally leukotoxic strains. This finding suggests that LtxA might play a key role in A. actinomycetemcomitans pathogenicity. Because of this correlation, much work over the past 30 years has been focused on understanding the mechanisms by which LtxA interacts with and kills host cells. In this article, we review those findings, highlight the remaining open questions, and demonstrate how knowledge of these mechanisms, particularly the toxin's interactions with lymphocyte function-associated antigen-1 (LFA-1) and cholesterol, enables the design of targeted anti-LtxA strategies to prevent/treat disease.
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Affiliation(s)
- Eric Krueger
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
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Chang EH, Giaquinto P, Huang J, Balashova NV, Brown AC. Epigallocatechin gallate inhibits leukotoxin release by Aggregatibacter actinomycetemcomitans by promoting association with the bacterial membrane. Mol Oral Microbiol 2020; 35:29-39. [PMID: 31816197 PMCID: PMC7015128 DOI: 10.1111/omi.12275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 12/21/2022]
Abstract
The oral pathogen, Aggregatibacter actinomycetemcomitans, produces a number of virulence factors, including a leukotoxin (LtxA), which specifically kills human white blood cells, to provide a colonization advantage to the bacterium. Strains of A. actinomycetemcomitans that produce more LtxA have been more closely linked to disease, indicating that this toxin plays a key role in pathogenesis of the bacterium. Disruption of the activity of LtxA thus represents a promising approach to reducing the pathogenicity of the bacterium. Catechins are polyphenolic molecules derived from plants, which have shown potent antibacterial and antitoxin activities. We have previously shown that galloylated catechins are able to prevent LtxA delivery to host cells by altering the toxin's secondary structure and preventing binding to cholesterol on the host cell membrane. Here, we have investigated how one particular galloylated catechin, epigallocatechin gallate (EGCg), affects A. actinomycetemcomitans growth and toxin secretion. Our results demonstrate that EGCg, at micromolar concentrations, inhibits A. actinomycetemcomitans growth, as has been reported for other bacterial species. At subinhibitory concentrations, EGCg promotes LtxA production, but the toxicity of the bacterial supernatant against human immune cells is reduced. The results of our biophysical studies indicate that this seemingly contradictory result is caused by an EGCg-mediated enhancement of LtxA affinity for the bacterial cell surface. Together, these results demonstrate the potential of EGCg in the treatment of virulent A. actinomycetemcomitans infections.
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Affiliation(s)
- En Hyung Chang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Peter Giaquinto
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Joanne Huang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Nataliya V. Balashova
- Department of Basic and Translational Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, 19104
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
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RTX Toxins Ambush Immunity's First Cellular Responders. Toxins (Basel) 2019; 11:toxins11120720. [PMID: 31835552 PMCID: PMC6950748 DOI: 10.3390/toxins11120720] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 01/17/2023] Open
Abstract
The repeats-in-toxin (RTX) family represents a unique class of bacterial exoproteins. The first family members described were toxins from Gram-negative bacterial pathogens; however, additional members included exoproteins with diverse functions. Our review focuses on well-characterized RTX family toxins from Aggregatibacteractinomycetemcomitans (LtxA), Mannheimiahaemolytica (LktA), Bordetella pertussis (CyaA), uropathogenic Escherichia coli (HlyA), and Actinobacillus pleuropneumoniae (ApxIIIA), as well as the studies that have honed in on a single host cell receptor for RTX toxin interactions, the β2 integrins. The β2 integrin family is composed of heterodimeric members with four unique alpha subunits and a single beta subunit. β2 integrins are only found on leukocytes, including neutrophils and monocytes, the first responders to inflammation following bacterial infection. The LtxA, LktA, HlyA, and ApxIIIA toxins target the shared beta subunit, thereby targeting all types of leukocytes. Specific β2 integrin family domains are required for the RTX toxin’s cytotoxic activity and are summarized here. Research examining the domains of the RTX toxins required for cytotoxic and hemolytic activity is also summarized. RTX toxins attack and kill phagocytic immune cells expressing a single integrin family, providing an obvious advantage to the pathogen. The critical question that remains, can the specificity of the RTX-β2 integrin interaction be therapeutically targeted?
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Belibasakis GN, Maula T, Bao K, Lindholm M, Bostanci N, Oscarsson J, Ihalin R, Johansson A. Virulence and Pathogenicity Properties of Aggregatibacter actinomycetemcomitans. Pathogens 2019; 8:E222. [PMID: 31698835 PMCID: PMC6963787 DOI: 10.3390/pathogens8040222] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023] Open
Abstract
Aggregatibacter actinomycetemcomitans is a periodontal pathogen colonizing the oral cavity of a large proportion of the human population. It is equipped with several potent virulence factors that can cause cell death and induce or evade inflammation. Because of the large genetic diversity within the species, both harmless and highly virulent genotypes of the bacterium have emerged. The oral condition and age, as well as the geographic origin of the individual, influence the risk to be colonized by a virulent genotype of the bacterium. In the present review, the virulence and pathogenicity properties of A. actinomycetemcomitans will be addressed.
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Affiliation(s)
- Georgios N. Belibasakis
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Terhi Maula
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland; (T.M.); (R.I.)
| | - Kai Bao
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Mark Lindholm
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
| | - Nagihan Bostanci
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Jan Oscarsson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
| | - Riikka Ihalin
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland; (T.M.); (R.I.)
| | - Anders Johansson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
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Differential Cell Lysis Among Periodontal Strains of JP2 and Non-JP2 Genotype of Aggregatibacter actinomycetemcomitans Serotype B Is Not Reflected in Dissimilar Expression and Production of Leukotoxin. Pathogens 2019; 8:pathogens8040211. [PMID: 31671616 PMCID: PMC6963569 DOI: 10.3390/pathogens8040211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/25/2019] [Accepted: 10/26/2019] [Indexed: 01/13/2023] Open
Abstract
Leukotoxic potential of Aggregatibacter actinomycetemcomitans strains has been studied by the use of several methods, and results differ depending on the methods used. The aim of the present study was to perform a comprehensive examination of the leukotoxic potential of a collection of A. actinomycetemcomitans strains by use of three quantitative methods, Western blotting, ELISA, and mRNA expression assay and compare these results with previous data obtained by a cell lysis assay. A higher leukotoxic potential among JP2 genotype strains compared to non-JP2 genotype strains of A. actinomycetemcomitans was found by Western blotting, ELISA and mRNA expression assay. Leukotoxicity as determined by cell lysis assay showed a variation among strains examined, not only depending on being part of JP2 genotype vs. non-JP2 genotype group of A. actinomycetemcomitans. The leukotoxicity of A. actinomycetemcomitans strains as determined by cell lysis assay did not correspond to the leukotoxic potential of A. actinomycetemcomitans strains as determined by three quantitative methods. A comparison of the results obtained by ELISA and mRNA expression assay showed a reasonable correlation between these two methods. It seems important to use more than one method to assess the LtxA-related virulence capacity of A. actinomycetemcomitans in order to obtain comprehensive understanding of the leukotoxic potential of A. actinomycetemcomitans strains.
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Aggregatibacter actinomycetemcomitans Leukotoxin (LtxA) Requires Death Receptor Fas, in Addition to LFA-1, To Trigger Cell Death in T Lymphocytes. Infect Immun 2019; 87:IAI.00309-19. [PMID: 31109948 DOI: 10.1128/iai.00309-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 05/10/2019] [Indexed: 11/20/2022] Open
Abstract
Leukotoxin (LtxA) (trade name, Leukothera) is a protein secreted by the oral bacterium Aggregatibacter actinomycetemcomitans A. actinomycetemcomitans is an oral pathogen strongly associated with development of localized aggressive periodontitis. LtxA acts as a virulence factor for A. actinomycetemcomitans by binding to the β2 integrin lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) on white blood cells (WBCs) and causing cell death. In addition, because of its specificity for malignant and activated WBCs, LtxA is being investigated as a therapeutic agent for treatment of hematological malignancies and autoimmune diseases. Here, we report the successful generation and characterization of Jurkat T lymphocytes with deletions in CD18, CD11a, and Fas that were engineered using CRISPR/Cas9 gene editing. Using these clones, we demonstrate the specificity of LtxA for cells expressing LFA-1. We also demonstrate the requirement of the cell death receptor Fas for LtxA-mediated cell death in T lymphocytes. We show that LFA-1 and Fas are early events in the LtxA-mediated cell death cascade as caspase activation and mitochondrial perturbation do not occur in the absence of either receptor. To our knowledge, LtxA is the first molecule, other than FasL, known to require the Fas death receptor to initiate cell death. Knowledge of the mechanism of cell death induced by LtxA will facilitate the understanding of LtxA as a bacterial virulence factor and development of it as a potential therapeutic agent.
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Oscarsson J, Claesson R, Lindholm M, Höglund Åberg C, Johansson A. Tools of Aggregatibacter actinomycetemcomitans to Evade the Host Response. J Clin Med 2019; 8:E1079. [PMID: 31336649 PMCID: PMC6678183 DOI: 10.3390/jcm8071079] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/08/2019] [Accepted: 07/18/2019] [Indexed: 02/06/2023] Open
Abstract
Periodontitis is an infection-induced inflammatory disease that affects the tooth supporting tissues, i.e., bone and connective tissues. The initiation and progression of this disease depend on dysbiotic ecological changes in the oral microbiome, thereby affecting the severity of disease through multiple immune-inflammatory responses. Aggregatibacter actinomycetemcomitans is a facultative anaerobic Gram-negative bacterium associated with such cellular and molecular mechanisms associated with the pathogenesis of periodontitis. In the present review, we outline virulence mechanisms that help the bacterium to escape the host response. These properties include invasiveness, secretion of exotoxins, serum resistance, and release of outer membrane vesicles. Virulence properties of A. actinomycetemcomitans that can contribute to treatment resistance in the infected individuals and upon translocation to the circulation, also induce pathogenic mechanisms associated with several systemic diseases.
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Affiliation(s)
- Jan Oscarsson
- Department of Odontology, Oral Microbiology, Umeå University, S-90187 Umeå, Sweden
| | - Rolf Claesson
- Department of Odontology, Oral Microbiology, Umeå University, S-90187 Umeå, Sweden
| | - Mark Lindholm
- Department of Odontology, Oral Microbiology, Umeå University, S-90187 Umeå, Sweden
| | - Carola Höglund Åberg
- Department of Odontology, Molecular Periodontology, Umeå University, S-901 87 Umeå, Sweden
| | - Anders Johansson
- Department of Odontology, Molecular Periodontology, Umeå University, S-901 87 Umeå, Sweden.
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Krueger E, Brown AC. Inhibition of bacterial toxin recognition of membrane components as an anti-virulence strategy. J Biol Eng 2019; 13:4. [PMID: 30820243 PMCID: PMC6380060 DOI: 10.1186/s13036-018-0138-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/27/2018] [Indexed: 12/21/2022] Open
Abstract
Over recent years, the development of new antibiotics has not kept pace with the rate at which bacteria develop resistance to these drugs. For this reason, many research groups have begun to design and study alternative therapeutics, including molecules to specifically inhibit the virulence of pathogenic bacteria. Because many of these pathogenic bacteria release protein toxins, which cause or exacerbate disease, inhibition of the activity of bacterial toxins is a promising anti-virulence strategy. In this review, we describe several approaches to inhibit the initial interactions of bacterial toxins with host cell membrane components. The mechanisms by which toxins interact with the host cell membrane components have been well-studied over the years, leading to the identification of therapeutic targets, which have been exploited in the work described here. We review efforts to inhibit binding to protein receptors and essential membrane lipid components, complex assembly, and pore formation. Although none of these molecules have yet been demonstrated in clinical trials, the in vitro and in vivo results presented here demonstrate their promise as novel alternatives and/or complements to traditional antibiotics.
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Affiliation(s)
- Eric Krueger
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015 USA
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015 USA
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