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Molli VLP, Kissa J, Baraniya D, Gharibi A, Chen T, Al-Hebshi NN, Albandar JM. Bacteriome analysis of Aggregatibacter actinomycetemcomitans-JP2 genotype-associated Grade C periodontitis in Moroccan adolescents. FRONTIERS IN ORAL HEALTH 2023; 4:1288499. [PMID: 38033462 PMCID: PMC10682098 DOI: 10.3389/froh.2023.1288499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
Background Grade C (previously aggressive) periodontitis (GCP) in adolescents is prevalent in certain parts of Africa where it is associated with JP2 genotype, a highly virulent strain of Aggregatibacter actinomycetemcomitans. The aim of this study was to characterize the subgingival bacteriome in Moroccan subjects with GCP positive to A. actinomycetemcomitans JP2 genotype. Methods Subgingival plaque samples were collected from shallow and deep pockets of 8 subjects with GCP (17.2 ± 1.5 years) and from gingival sulci of 13 controls with no periodontitis (14.6 ± 1.1 years). Identification and genotyping of A. actinomycetemcomitans was performed using PCR analysis of the ltx operon, while bacteriome profiling was done by 16S rRNA gene sequencing (V1-V3 region). Groups were compared in terms of microbial diversity, abundances, and dysbiosis. Results The shallow and deep pocket sites from GCP cases had a significantly altered microbial composition compared to controls. Species associated with health included Haemophilus parainfluenzae, Lautropia mirabilis, Streptococcus spp., Gemella spp., and Rothia spp. While known periodontal pathogens, including Porphyromonas gingivalis, Tannerella forsythia, Treponema spp. and Fretibacterium spp., were significantly enriched in GCP, non-conventional taxa, including Pseudomonas oral taxon C61 and Enterobacter cloacae were more abundant and showed stronger association with the disease. Less significant differences in abundances of individual taxa were observed between shallow and deep pockets. Overall dysbiosis measured in terms of Subgingival Microbial Dysbiosis Index (SMDI) differentiated between GCP and no-periodontitis with 95% accuracy. Conclusions The results suggest that several periodontal pathogens involved in the adult-type periodontitis also play a role in JP2 genotype-associated GCP. The potential role of non-conventional taxa in the pathogenesis of GCP warrants further investigation.
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Affiliation(s)
- Vijaya Lakshmi Pavani Molli
- Department of Periodontology and Oral Implantology, Maurice H. Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
| | - Jamila Kissa
- Department of Periodontology, Faculty of Dental Medicine, University of Hassan II, Casablanca, Morocco
| | - Divyashri Baraniya
- Oral Microbiome Research Laboratory, Maurice H. Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
| | - Amina Gharibi
- Department of Periodontology, Faculty of Dental Medicine, University of Hassan II, Casablanca, Morocco
| | - Tsute Chen
- Department of Microbiology, Forsyth Institute, Cambridge, MA, United States
| | - Nezar N. Al-Hebshi
- Oral Microbiome Research Laboratory, Maurice H. Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
| | - Jasim M. Albandar
- Department of Periodontology and Oral Implantology, Maurice H. Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
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Kim J, Kim BS. Bacterial Sialic Acid Catabolism at the Host–Microbe Interface. J Microbiol 2023; 61:369-377. [PMID: 36972004 DOI: 10.1007/s12275-023-00035-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/27/2023] [Accepted: 03/06/2023] [Indexed: 03/29/2023]
Abstract
Sialic acids consist of nine-carbon keto sugars that are commonly found at the terminal end of mucins. This positional feature of sialic acids contributes to host cell interactions but is also exploited by some pathogenic bacteria in evasion of host immune system. Moreover, many commensals and pathogens use sialic acids as an alternative energy source to survive within the mucus-covered host environments, such as the intestine, vagina, and oral cavity. Among the various biological events mediated by sialic acids, this review will focus on the processes necessary for the catabolic utilization of sialic acid in bacteria. First of all, transportation of sialic acid should be preceded before its catabolism. There are four types of transporters that are used for sialic acid uptake; the major facilitator superfamily (MFS), the tripartite ATP-independent periplasmic C4-dicarboxilate (TRAP) multicomponent transport system, the ATP binding cassette (ABC) transporter, and the sodium solute symporter (SSS). After being moved by these transporters, sialic acid is degraded into an intermediate of glycolysis through the well-conserved catabolic pathway. The genes encoding the catabolic enzymes and transporters are clustered into an operon(s), and their expression is tightly controlled by specific transcriptional regulators. In addition to these mechanisms, we will cover some researches about sialic acid utilization by oral pathogens.
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Affiliation(s)
- Jaeeun Kim
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Byoung Sik Kim
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, 03760, Republic of Korea.
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3
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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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4
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Belibasakis GN, Belstrøm D, Eick S, Gursoy UK, Johansson A, Könönen E. Periodontal microbiology and microbial etiology of periodontal diseases: Historical concepts and contemporary perspectives. Periodontol 2000 2023. [PMID: 36661184 DOI: 10.1111/prd.12473] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/21/2022] [Accepted: 09/06/2022] [Indexed: 01/21/2023]
Abstract
This narrative review summarizes the collective knowledge on periodontal microbiology, through a historical timeline that highlights the European contribution in the global field. The etiological concepts on periodontal disease culminate to the ecological plaque hypothesis and its dysbiosis-centered interpretation. Reference is made to anerobic microbiology and to the discovery of select periodontal pathogens and their virulence factors, as well as to biofilms. The evolution of contemporary molecular methods and high-throughput platforms is highlighted in appreciating the breadth and depth of the periodontal microbiome. Finally clinical microbiology is brought into perspective with the contribution of different microbial species in periodontal diagnosis, the combination of microbial and host biomarkers for this purpose, and the use of antimicrobials in the treatment of the disease.
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Affiliation(s)
- Georgios N Belibasakis
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Daniel Belstrøm
- Section for Clinical Oral Microbiology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sigrun Eick
- Department of Periodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Ulvi K Gursoy
- Department of Periodontology, Institute of Dentistry, University of Turku, Turku, Finland
| | | | - Eija Könönen
- Department of Periodontology, Institute of Dentistry, University of Turku, Turku, Finland
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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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Hashai K, Chapple IL, Shapira L, Assadi W, Dadon S, Polak D. CD18 Mediates Neutrophil Imperviousness to the Aggregatibacter actinomycetemcomitans JP2 Clone in Molar-Incisor Pattern Periodontitis. Front Immunol 2022; 13:847372. [PMID: 35663998 PMCID: PMC9159298 DOI: 10.3389/fimmu.2022.847372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 04/04/2022] [Indexed: 11/23/2022] Open
Abstract
Introduction Molar-incisor pattern periodontitis (MIPP) in the absence of significant local risk factors or systemic disease, is a rare, early onset periodontal disease phenotype, with 0.5% to 2.5% global prevalence. The condition is characterized by impaired neutrophil function and persistent Aggregatibacter actinomycetemcomitans (JP2 clone) infection. The aim of this study was to characterize neutrophil functional responses to JP2 and to investigate the neutrophil receptors involved. Materials and Methods Neutrophils were obtained from whole blood samples of periodontally healthy and MIPP subjects and incubated with the JP2 clone or a non-JP2 clone of A. actinomycetemcomitans. Bacterial survival was tested by blood agar culture; neutrophil death was tested with propidium iodide and flow cytometry; Reactive oxygen production (ROS) was measured with 2′,7′-dichlorofluorescein diacetate and a fluorescence plate reader; the cytokinome was analysed using an array profiler, ELISA and RT-PCR. Receptors binding to JP2 were isolated using a novel immunoprecipitation assay and validated functionally using specific blocking antibodies. Results JP2 and non-JP2 survival was comparable between all the neutrophil groups. Resistance to neutrophil necrosis following exposure to JP2 was significantly lower in the MIPP group, than in all the other groups (p<0.0001). Conversely, MIPP neutrophils showed lower levels of ROS production in response to JP2 infection compared with that of healthy neutrophils (p<0.001). Furthermore, significantly lower levels of cytokines, such as IL8, IL10 and TNFα, were observed during JP2 incubation with MIPP neutrophils than upon incubation with periodontally healthy neutrophils. Various proteins expressed on neutrophils bind to JP2. Of these, CD18 was found to mediate neutrophil necrosis. The CD18 receptor on MIPP neutrophils acts differently from that on periodontally healthy patients neutrophils, and appears to reflect differential neutrophil reactions to JP2. Conclusion This study portrays a fundamental difference in neutrophil response to JP2 infection between periodontally healthy and MIPP patients. This was evident in the resistance to necrosis, and lower ROS and cytokine production, despite the persistent presence of viable JP2. Whilst in periodontally healthy neutrophils, JP2 binds to CD18 on cell surfaces, this is not the case in MIPP neutrophils, suggesting a potential role for CD18 in the periodontal susceptibility of MIPP patients.
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Affiliation(s)
- Koren Hashai
- Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Periodontics, Hadassah Medical Center, Jerusalem, Israel
| | - Ian L Chapple
- Institute of Clinical Sciences, College of Medical and Dental Sciences, School of Dentistry, University of Birmingham, Birmingham, United Kingdom.,Birmingham Community Healthcare National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
| | - Lior Shapira
- Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Periodontics, Hadassah Medical Center, Jerusalem, Israel
| | - Walaa Assadi
- Department of Orthodontics, Rambam Medical Center, Haifa, Israel
| | - Stav Dadon
- Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Orthodontics, Hadassah Medical Center, Jerusalem, Israel
| | - David Polak
- Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Periodontics, Hadassah Medical Center, Jerusalem, Israel
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7
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Granlund M, Åberg CH, Johansson A, Claesson R. Discrepancies in Antimicrobial Susceptibility between the JP2 and the Non-JP2 Genotype of Aggregatibacter actinomycetemcomitans. Antibiotics (Basel) 2022; 11:antibiotics11030317. [PMID: 35326780 PMCID: PMC8944592 DOI: 10.3390/antibiotics11030317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 12/04/2022] Open
Abstract
The Aggregatibacter actinomycetemcomitans JP2 genotype is associated with high leukotoxin production and severe (aggressive) periodontitis. The aim of this study was to compare the antimicrobial susceptibility of JP2 and non-JP2 genotype strains. Minimal inhibitory concentrations (MICs) of 11 antimicrobials were determined for 160 A. actinomycetemcomitans of serotype a, b, or c, mostly isolated in Sweden or Ghana. MIC distributions for benzylpenicillin and fusidic acid revealed a more susceptible subpopulation for 38 serotype b strains, including the 32 of the JP2 genotype, with a benzylpenicillin MIC range of 0.125−0.5 mg/L. In contrast, benzylpenicillin MIC ≤ 16 mg/L was the estimated 99.5% epidemiological cutoff (ECOFF) of all strains. Beta-lactamase production was not detected. The fusidic acid MIC distribution of 11 strains of Aggregatibacter aphrophilus agreed with that found in non-JP2 strains. Cefotaxime, meropenem, levofloxacin, and trimethoprim−sulfamethoxazole MICs were all ≤0.25 mg/L, while MIC90 values for amoxicillin, azithromycin and tetracycline were 1 mg/L. Metronidazole MICs varied between 0.5 and >256 mg/L. The discrepant findings indicate that A. actinomycetemcomitans may be divided into two separate wild types, with a suggested intrinsic reduced susceptibility for benzylpenicillin in the majority of non-JP2 genotype strains. Possible implications for the treatment of A. actinomycetemcomitans infections are discussed.
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Affiliation(s)
- Margareta Granlund
- Department of Clinical Microbiology, Umeå University, S-90187 Umeå, Sweden;
| | - Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (C.H.Å.); (A.J.)
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (C.H.Å.); (A.J.)
| | - Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden
- Correspondence: ; Tel.:+76-70-3090126
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8
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Prevalence of the JP2 genotype of Aggregatibacter actinomycetemcomitans in the world population: a systematic review. Clin Oral Investig 2022; 26:2317-2334. [DOI: 10.1007/s00784-021-04343-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/09/2021] [Indexed: 12/11/2022]
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9
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Hbibi A, Bouziane A, Lyoussi B, Zouhdi M, Benazza D. Aggregatibacter actinomycetemcomitans: From Basic to Advanced Research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1373:45-67. [DOI: 10.1007/978-3-030-96881-6_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Claesson R, Johansson A, Höglund Åberg C, Esberg A, Haubek D, Oscarsson J. Multilocus Sequence Typing of Non-JP2 Serotype b Aggregatibacter actinomycetemcomitans Strains of Ghanaian and Swedish Origin. Front Cell Infect Microbiol 2022; 11:769671. [PMID: 34970507 PMCID: PMC8712761 DOI: 10.3389/fcimb.2021.769671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/26/2021] [Indexed: 11/21/2022] Open
Abstract
Objective and Methods The Gram-negative bacterium, Aggregatibacter actinomycetemcomitans is associated with periodontitis affecting young individuals. The geographic dissemination of the highly leukotoxic JP2 genotype of serotype b of this species was previously studied by multilocus sequence typing (MLST). Here, we have used MLST to genetically characterize non-JP2 genotype strains of serotype b, isolated from individuals living in Ghana (n=41), and in Sweden (n=13), respectively. Results The MLST analysis revealed a total of nine sequence types (ST). Both Ghanaian and Swedish isolates were distributed in ST 1-3. ST 5 and 6 were only identified among the Ghanaian strains, whereas ST 4, 7, 8 and 9 were uniquely represented among the Swedish strains. Previously, we characterized these non-JP2 genotype strains of A. actinomycetemcomitans serotype b by arbitrarily-primed (AP)-PCR, which distributed them into three groups, AP-PCR type 1, 2, and 3, respectively. AP-PCR type 1 strains are generally highly leukotoxic, and are associated with progression of periodontal attachment loss. As AP-PCR type 1 includes both JP2 genotype strains and a proportion of non-JP2 genotype strains of serotype b, a straightforward diagnostic procedure has been sought. This has revealed a gene, cagE, which appears to be conserved only in this AP-PCR type. According to our results, MLST was not a highly discriminatory method to identify AP-PCR type 1, as strains of this AP-PCR type could be found within three different ST: ST 2, ST 3 and ST 8. Conclusion According to MLST, a geographic dissemination of non-JP2 genotype A. actinomycetemcomitans serotype b appears to exist. However, aiming to identify carriers of AP-PCR type 1, non-JP2 genotype serotype b, PCR with cagE-specific primers is likely the most efficient diagnostic procedure known today.
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Affiliation(s)
- Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Anders Esberg
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Dorte Haubek
- Section for Paediatric Dentistry, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Jan Oscarsson
- Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
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Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures. J Clin Med 2021; 10:jcm10225402. [PMID: 34830683 PMCID: PMC8621963 DOI: 10.3390/jcm10225402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. METHODS A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. RESULTS AND CONCLUSIONS The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.
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12
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Alghamdi MA, Redwan EM. Interplay of Microbiota and Citrullination in the Immunopathogenesis of Rheumatoid Arthritis. Probiotics Antimicrob Proteins 2021; 14:99-113. [PMID: 34036479 DOI: 10.1007/s12602-021-09802-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2021] [Indexed: 12/18/2022]
Abstract
Microbiota is a balanced ecosystem that has important functions to the host health including development, defense, digestion, and absorption of dietary fibers and minerals, vitamin synthesizes, protection, and training the host immune system. On the other hand, its dysbiosis is linked to many human diseases such as rheumatoid arthritis (RA). The RA is an inflammatory autoimmune disorder caused by genetic and environmental factors; microbiota may be considered as a risk environmental factor for it. Citrullination is a post-translation modification (PMT) that converts the amino acid arginine to amino acid citrulline in certain proteins. These citrullinated proteins are recognized as a foreign antigen by the immune system resulting in the upregulation of inflammatory action such as in RA. The current work highlights the effect of both gut and oral microbiota dysbiosis on the development of RA, as well as discusses how the alteration in microbiota composition leads to the overgrowth of some bacterial species that entangled in RA pathogenicity. The evidence suggested that some oral and gut microbial species such as Porphyromonas gingivalis and Prevotella copri, respectively, contribute to RA pathogenesis. During dysbiosis, these bacteria can mediate the citrullination of either human or bacteria proteins to trigger an immune response that leads to the generation of autoantibodies.
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Affiliation(s)
- Mohammed A Alghamdi
- Biological Science Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.,Laboratory Department, University Medical Services Center, King Abdulaziz University, P.O. Box 80200, Jeddah, 21589, Saudi Arabia
| | - Elrashdy M Redwan
- Biological Science Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia. .,Therapeutic and Protective Proteins Laboratory, Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications, New Borg EL-Arab, Alexandria, 21934, Egypt.
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13
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Betancur D, Muñoz Grez C, Oñate A. Comparative Analysis of Cytokine Expression in Oral Keratinocytes and THP-1 Macrophages in Response to the Most Prevalent Serotypes of Aggregatibacter actinomycetemcomitans. Microorganisms 2021; 9:622. [PMID: 33802988 PMCID: PMC8002688 DOI: 10.3390/microorganisms9030622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Periodontitis is a chronic inflammatory disease associated with a dysbiotic biofilm. Many pathogens have been related with its progression and severity, one of which is Aggregatibacter actinomycetemcomitans, a Gram-negative bacteria with seven serotypes (a-g) according with the structure of its LPS, with serotype b defined as the most virulent compared with the other serotypes. The aim of this study was to evaluate the response of oral keratinocytes and macrophages to A. actinomycetemcomitans. METHODS Oral keratinocytes (OKF6/TERT2) and macrophages (THP-1) were infected with A. actinomycetemcomitans serotypes a, b and c. The expression of IL-1β, IL-6, IL-8, IL-18, TNF-α, MMP-9, RANKL, TLR-2, TLR-4, TLR-6, thymic stromal lymphopoietin (TSLP), and ICAM-1 was evaluated by qPCR at 2 and 24 h after infection. RESULTS An increase in the expression of these molecules was induced by all serotypes at both times of infection, with macrophages showing higher levels of expression at 24 h compared to epithelial cells in which the highest levels were observed in the first hours after infection. CONCLUSIONS Keratinocytes and macrophages contribute to the inflammation in periodontitis from the early stages of infection, producing the first waves of cytokines, acting as the first signal for professional immune cell recruitment and modulation of more specific immune responses.
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Affiliation(s)
| | | | - Angel Oñate
- Laboratory of Molecular Immunology, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción 4030000, Chile; (D.B.); (C.M.G.)
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14
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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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15
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Jensen AB, Isidor F, Lund M, Væth M, Johansson A, Lauritsen NN, Haubek D. Prevalence of Aggregatibacter actinomycetemcomitans and Periodontal Findings among 14 to 15-Year Old Danish Adolescents: A Descriptive Cross-Sectional Study. Pathogens 2020; 9:pathogens9121054. [PMID: 33339288 PMCID: PMC7765784 DOI: 10.3390/pathogens9121054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/08/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans (Aa) is a keystone pathogen associated with periodontitis in adolescents. The knowledge on the prevalence of Aa and periodontitis among adolescents in Northern Europe is sparse. A total of 525 14- to 15-year-old adolescents from the municipality of Aarhus, Denmark, underwent a full-mouth clinical examination. Plaque score (PS), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded. Subgingival plaque samples (SPS) and stimulated saliva samples (SSS) were collected and analyzed for the presence of JP2 and non-JP2 genotypes of Aa using real-time PCR. A total of 70 (13.3%) individuals were positive for Aa, with 17 found in SPS, 19 in SSS, and 35 in both. The highly leukotoxic JP2 genotype of Aa was not detected. The individuals positive for Aa in both SPS and SSS had poorer periodontal outcomes (PPD and CAL) than individuals without Aa and individuals carrying Aa in either SPS or SSS only. In conclusion, 13% of 14- to 15-year-old Danish adolescents were positive for Aa, and the presence of Aa in both SPS and SSS was associated with poorer periodontal outcomes.
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Affiliation(s)
- Anne Birkeholm Jensen
- Section for Pediatric Dentistry, Department of Dentistry and Oral Health, Health, Aarhus University, 8000 Aarhus, Denmark;
- The Municipality of Aarhus, 8000 Aarhus, Denmark
| | - Flemming Isidor
- Section for Prosthetic Dentistry, Department of Dentistry and Oral Health, Health, Aarhus University, 8000 Aarhus, Denmark
| | - Marianne Lund
- Department of Clinical Microbiology, Aarhus University Hospital, Skejby, 8210 Aarhus, Denmark;
| | - Michael Væth
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark;
| | - Anders Johansson
- Divison of Molecular Periodontology, Department of Odontology, Faculty of Medicine and Odontology, Umea University, 901 87 Umea, Sweden;
| | | | - Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry and Oral Health, Health, Aarhus University, 8000 Aarhus, Denmark;
- Correspondence: ; Tel.: +45-21-685-848
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16
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Monasterio G, Castillo F, Astorga J, Hoare A, Terraza-Aguirre C, Cafferata EA, Villablanca EJ, Vernal R. O-Polysaccharide Plays a Major Role on the Virulence and Immunostimulatory Potential of Aggregatibacter actinomycetemcomitans During Periodontal Infection. Front Immunol 2020; 11:591240. [PMID: 33193431 PMCID: PMC7662473 DOI: 10.3389/fimmu.2020.591240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/06/2020] [Indexed: 01/09/2023] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative oral bacterium with high immunostimulatory and pathogenic potential involved in the onset and progression of periodontitis, a chronic disease characterized by aberrant immune responses followed by tooth-supporting bone resorption, which eventually leads to tooth loss. While several studies have provided evidence related to the virulence factors of A. actinomycetemcomitans involved in the host cell death and immune evasion, such as its most studied primate-specific virulence factor, leukotoxin, the role of specific lipopolysaccharide (LPS) domains remain poorly understood. Here, we analyzed the role of the immunodominant domain of the LPS of A. actinomycetemcomitans termed O-polysaccharide (O-PS), which differentiates the distinct bacterial serotypes based on its antigenicity. To determine the role of the O-PS in the immunogenicity and virulence of A. actinomycetemcomitans during periodontitis, we analyzed the in vivo and in vitro effect of an O-PS-defective transposon mutant serotype b strain, characterized by the deletion of the rmlC gene encoding the α-L-rhamnose sugar biosynthetic enzyme. Induction of experimental periodontitis using the O-PS-defective rmlC mutant strain resulted in lower tooth-supporting bone resorption, infiltration of Th1, Th17, and Th22 lymphocytes, and expression of Ahr, Il1b, Il17, Il23, Tlr4, and RANKL (Tnfsf11) in the periodontal lesions as compared with the wild-type A. actinomycetemcomitans strain. In addition, the O-PS-defective rmlC mutant strain led to impaired activation of antigen-presenting cells, with less expression of the co-stimulatory molecules CD40 and CD80 in B lymphocytes and dendritic cells, and downregulated expression of Tnfa and Il1b in splenocytes. In conclusion, these data demonstrate that the O-PS from the serotype b of A. actinomycetemcomitans plays a key role in the capacity of the bacterium to prime oral innate and adaptive immune responses, by triggering the Th1 and Th17-driven tooth-supporting bone resorption during periodontitis.
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Affiliation(s)
- Gustavo Monasterio
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Division of Immunology and Allergy, Department of Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center for Molecular Medicine, Stockholm, Sweden
| | - Francisca Castillo
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Jessica Astorga
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Anilei Hoare
- Oral Microbiology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Claudia Terraza-Aguirre
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Institute for Regenerative Medicine and Biotherapies (IRMB), Université de Montpellier, Montpellier, France
| | - Emilio A Cafferata
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Department of Periodontology, School of Dentistry, Universidad Científica del Sur, Lima, Perú
| | - Eduardo J Villablanca
- Division of Immunology and Allergy, Department of Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center for Molecular Medicine, Stockholm, Sweden
| | - Rolando Vernal
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
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Amado PPP, Kawamoto D, Albuquerque-Souza E, Franco DC, Saraiva L, Casarin RCV, Horliana ACRT, Mayer MPA. Oral and Fecal Microbiome in Molar-Incisor Pattern Periodontitis. Front Cell Infect Microbiol 2020; 10:583761. [PMID: 33117737 PMCID: PMC7578221 DOI: 10.3389/fcimb.2020.583761] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022] Open
Abstract
In order to improve our understanding on the microbial complexity associated with Grade C/molar-incisor pattern periodontitis (GC/MIP), we surveyed the oral and fecal microbiomes of GC/MIP and compared to non-affected individuals (Control). Seven Afro-descendants with GC/MIP and seven age/race/gender-matched controls were evaluated. Biofilms from supra/subgingival sites (OB) and feces were collected and submitted to 16S rRNA sequencing. Aggregatibacter actinomycetemcomitans (Aa) JP2 clone genotyping and salivary nitrite levels were determined. Supragingival biofilm of GC/MIP presented greater abundance of opportunistic bacteria. Selenomonas was increased in subgingival healthy sites of GC/MIP compared to Control. Synergistetes and Spirochaetae were more abundant whereas Actinobacteria was reduced in OB of GC/MIP compared to controls. Aa abundance was 50 times higher in periodontal sites with PD≥ 4 mm of GC/MIP than in controls. GC/MIP oral microbiome was characterized by a reduction in commensals such as Kingella, Granulicatella, Haemophilus, Bergeyella, and Streptococcus and enrichment in periodontopathogens, especially Aa and sulfate reducing Deltaproteobacteria. The oral microbiome of the Aa JP2-like+ patient was phylogenetically distant from other GC/MIP individuals. GC/MIP presented a higher abundance of sulfidogenic bacteria in the feces, such as Desulfovibrio fairfieldensis, Erysipelothrix tonsillarum, and Peptostreptococcus anaerobius than controls. These preliminary data show that the dysbiosis of the microbiome in Afro-descendants with GC/MIP was not restricted to affected sites, but was also observed in supragingival and subgingival healthy sites, as well as in the feces. The understanding on differences of the microbiome between healthy and GC/MIP patients will help in developing strategies to improve and monitor periodontal treatment.
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Affiliation(s)
- Pâmela Pontes Penas Amado
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Dione Kawamoto
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Emmanuel Albuquerque-Souza
- Division of Periodontology, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Diego Castillo Franco
- Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, São Paulo, Brazil.,Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
| | - Luciana Saraiva
- Division of Periodontology, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Renato Corrêa Viana Casarin
- Department of Prosthodontics and Periodontics, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil
| | | | - Marcia Pinto Alves Mayer
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,Division of Periodontology, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil
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18
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Pahumunto N, Basic A, Östberg AK, Teanpaisan R, Dahlen G. Oral Lactobacillus strains reduce cytotoxicity and cytokine release from peripheral blood mononuclear cells exposed to Aggregatibacter actinomycetemcomitans subtypes in vitro. BMC Microbiol 2020; 20:279. [PMID: 32917132 PMCID: PMC7488720 DOI: 10.1186/s12866-020-01959-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/27/2020] [Indexed: 01/02/2023] Open
Abstract
Background This study evaluated the effect of oral lactobacilli on the cytotoxicity and cytokine release from peripheral blood mononuclear cells (PBMCs) when exposed to Aggregatibacter actinomycetemcomitans subtypes in vitro. The supernatants and cell wall extracts (CWEs) of eight A. actinomycetemcomitans strains, representing different subtypes, and three Lactobacillus strains were used. The PBMCs from six blood donors were exposed to supernatants and CWEs of A. actinomycetemcomitans or Lactobacillus strains alone or combinations and untreated cells as control. The cytotoxicity was determined by trypan blue exclusion method and IL-1β secretion by ELISA. TNF-α, IL-6, and IL-8 secretions were measured using Bioplex Multiplex Immunoassay. Results Supernatants or CWEs from all bacterial strains showed cytotoxicity and IL-1β secretion and the subtypes of A. actinomycetemcomitans showed generally a significantly higher effect on PBMCs than that of the Lactobacillus strains. Two highly toxic A. actinomycetemcomitans strains (JP2 and JP2-like) induced a higher response than all other strains. When combined, Lactobacillus significantly reduced the toxicity and the IL-1β secretion induced by A. acinomycetemcomitans. The effect varied between the subtypes and the reduction was highest for the JP2 and JP2-like strains. The Lactobacillus paracasei strain SD1 had a higher reducing effect than the other Lactobacillus strains. This strain had a consistent reducing effect on all subtypes of A. actinomycetemcomitans cytotoxicity, and release of IL-1β, IL-6, IL-8, and TNF-α from PBMCs of the blood donors. A strong and significant variation in cytokine release between the six blood donors was noticed. Conclusions Lactobacillus spp. and L. paracasei SD1 in particular, showed a limited but statistically significant reducing interaction with A. actinomycetemcomitans toxicity and release of cytokines in vitro.
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Affiliation(s)
- Nuntiya Pahumunto
- Common Oral Diseases and Epidemiology Research Center and Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Thailand
| | - Amina Basic
- Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anna-Karin Östberg
- Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Rawee Teanpaisan
- Common Oral Diseases and Epidemiology Research Center and Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Thailand
| | - Gunnar Dahlen
- Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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Claesson R, Chiang HM, Lindholm M, Höglund Åberg C, Haubek D, Johansson A, Oscarsson J. Characterization of Aggregatibacter actinomycetemcomitans Serotype b Strains with Five Different, Including Two Novel, Leukotoxin Promoter Structures. Vaccines (Basel) 2020; 8:vaccines8030398. [PMID: 32698444 PMCID: PMC7563764 DOI: 10.3390/vaccines8030398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 01/23/2023] Open
Abstract
The JP2 genotype of A. actinomycetemcomitans, serotype b has attracted much interest during the past three decades due to its close association with periodontitis in young individuals and the enhanced expression of a leukotoxin (LtxA). A typical feature of this genotype is a 530-base pair (bp) deletion in the ltxCABD promoter region controlling leukotoxin expression. In the present work, we have characterized serotype b strains with four additional promoter types. Two novel types have been recognized, that is, one with a 230-bp deletion and one with a 172-bp duplication. Moreover, a strain with a 640-bp deletion and three strains with a full-length promoter, including the type strain Y4, were included in the present study. The seven strains were characterized by multi locus sequence typing (MLST) and arbitrarily primed polymerase chain reaction (PCR) and assessed for LtxA production. MLST showed that the strains with the non-JP2-like deletions represented distinct monophyletic groups, whereas the JP2 strain, HK1651, represented a separate branch. LtxA production was high in all three strains with a promoter deletion, whereas the other four strains showed significantly lower levels. It can be concluded that the genetic characterization and determination of LtxA production of A. actinomycetemcomitans isolates from individuals with periodontitis can contribute to the identification of novel virulent genotypes of this bacterium.
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Affiliation(s)
- Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (M.L.); (J.O.)
- Correspondence:
| | - Huei-Min Chiang
- Division of Molecular Periodontology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (H.-M.C.); (C.H.Å.); (A.J.)
| | - Mark Lindholm
- Division of Oral Microbiology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (M.L.); (J.O.)
| | - Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (H.-M.C.); (C.H.Å.); (A.J.)
| | - Dorte Haubek
- Section for Paediatric Dentistry, Department of Dentistry and Oral Health, Aarhus University, 8000 Aarhus, Denmark;
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (H.-M.C.); (C.H.Å.); (A.J.)
| | - Jan Oscarsson
- Division of Oral Microbiology, Department of Odontology, Umeå University, S-90187 Umeå, Sweden; (M.L.); (J.O.)
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20
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Aggregatibacter actinomycetemcomitans serotypes and JP2 outcomes related to clinical status over 6 years under periodontal maintenance therapy. Arch Oral Biol 2020; 116:104747. [PMID: 32422332 DOI: 10.1016/j.archoralbio.2020.104747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE This 6-year study evaluatedAggregatibacter actinomycetemcomitans outcomes and their relationship to clinical status. DESIGN From the eligible individuals (23-70 years of age), 31 regular compliers (between-visit interval < 6 months) were randomly selected and matched for age/sex with 31 irregular compliers (between-visit interval > 6 months). Periodontal clinical examination and subgingival samples were obtained 5 times: T1 (baseline), T2 (after active periodontal therapy), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria load, A. actinomycetemcomitans, and red complex species Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola levels were determined by qPCR while PCR was used to determine the occurrence of the a-b-c-d-e-f-g serotypes and the JP2 clone of A. actinomycetemcomitans. Data between groups was compared over time. RESULTS At baseline PCR revealed A. actinomycetemcomitans prevalence of 9.7 % and JP2 prevalence of 6.7 %. A. actinomycetemcomitans qPCR levels were higher among individuals < 35 years of age and increased at T2 in irregular compliers. At in irregular compliers at the three follow-up visits. Serotypes a, d, and f showed greater values in at least one follow-up visit in regular compliers. A. actinomycetemcomitans showed negative correlation with probing depth (PD) while serotype b showed negative correlations with PD, PI, clinical attachment level and red complex. CONCLUSIONS Longitudinally, compliance during PMT contributed to lower A. actinomycetemcomitans levels with some degree of correlation with clinical status. However, this study failed to report any positive effect on the occurrence of the most virulent representatives, i.e. serotype b and the JP2 clone.
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21
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Fert-Bober J, Darrah E, Andrade F. Insights into the study and origin of the citrullinome in rheumatoid arthritis. Immunol Rev 2019; 294:133-147. [PMID: 31876028 DOI: 10.1111/imr.12834] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/08/2019] [Indexed: 12/11/2022]
Abstract
The presence of autoantibodies and autoreactive T cells to citrullinated proteins and citrullinating enzymes in patients with rheumatoid arthritis (RA), together with the accumulation of citrullinated proteins in rheumatoid joints, provides substantial evidence that dysregulated citrullination is a hallmark feature of RA. However, understanding mechanisms that dysregulate citrullination in RA has important challenges. Citrullination is a normal process in immune and non-immune cells, which is likely activated by different conditions (eg, inflammation) with no pathogenic consequences. In a complex inflammatory environment such as the RA joint, unique strategies are therefore required to dissect specific mechanisms involved in the abnormal production of citrullinated proteins. Here, we will review current models of citrullination in RA and discuss critical components that, in our view, are relevant to understanding the accumulation of citrullinated proteins in the RA joint, collectively referred to as the RA citrullinome. In particular, we will focus on potential caveats in the study of citrullination in RA and will highlight methods to precisely detect citrullinated proteins in complex biological samples, which is a confirmatory approach to mechanistically link the RA citrullinome with unique pathogenic pathways in RA.
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Affiliation(s)
- Justyna Fert-Bober
- The Smidt Heart Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
| | - Erika Darrah
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Felipe Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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22
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Nørskov-Lauritsen N, Claesson R, Jensen AB, Åberg CH, Haubek D. Aggregatibacter Actinomycetemcomitans: Clinical Significance of a Pathobiont Subjected to Ample Changes in Classification and Nomenclature. Pathogens 2019; 8:E243. [PMID: 31752205 PMCID: PMC6963667 DOI: 10.3390/pathogens8040243] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/10/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium that is part of the oral microbiota. The aggregative nature of this pathogen or pathobiont is crucial to its involvement in human disease. It has been cultured from non-oral infections for more than a century, while its portrayal as an aetiological agent in periodontitis has emerged more recently. A. actinomycetemcomitans is one species among a plethora of microorganisms that constitute the oral microbiota. Although A. actinomycetemcomitans encodes several putative toxins, the complex interplay with other partners of the oral microbiota and the suppression of host response may be central for inflammation and infection in the oral cavity. The aim of this review is to provide a comprehensive update on the clinical significance, classification, and characterisation of A. actinomycetemcomitans, which has exclusive or predominant host specificity for humans.
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Affiliation(s)
| | - Rolf Claesson
- Department of Odontology, Division of Oral Microbiology, Umeå University, S-901 87 Umeå, Sweden;
| | - Anne Birkeholm Jensen
- Department of Dentistry and Oral Health, Aarhus University, DK-8000 Aarhus C, Denmark;
| | - Carola Höglund Åberg
- Department of Odontology, Division of Molecular Periodontology, Umeå University, S-901 87 Umeå, Sweden
| | - Dorte Haubek
- Department of Dentistry and Oral Health, Aarhus University, DK-8000 Aarhus C, Denmark;
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23
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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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25
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Johansson A, Claesson R, Höglund Åberg C, Haubek D, Lindholm M, Jasim S, Oscarsson J. Genetic Profiling of Aggregatibacter actinomycetemcomitans Serotype B Isolated from Periodontitis Patients Living in Sweden. Pathogens 2019; 8:pathogens8030153. [PMID: 31533208 PMCID: PMC6789814 DOI: 10.3390/pathogens8030153] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/10/2019] [Accepted: 09/15/2019] [Indexed: 02/06/2023] Open
Abstract
The bacterium Aggregatibacter actinomycetemcomitans is associated with aggressive forms of periodontitis and with systemic diseases, such as endocarditis. By assessing a Ghanaian longitudinal adolescent cohort, we earlier recognized the cagE gene as a possible diagnostic marker for a subgroup of JP2 and non-JP2 genotype serotype b A. actinomycetemcomitans strains, associated with high leukotoxicity as determined in a semi-quantitative cell assay. This group of A. actinomycetemcomitans is associated with the progression of attachment loss. In the present work, we used conventional polymerase chain reaction (PCR) and quantitative PCR to perform the cagE genotyping of our collection of 116 selected serotype b A. actinomycetemcomitans strains, collected over a period of 15 years from periodontitis patients living in Sweden. The A. actinomycetemcomitans strains carrying cagE (referred to as cagE+; n = 49) were compared to the cagE-negative strains (n = 67), present at larger proportions in the subgingival plaque samples, and were also much more prevalent in the young (≤35 years) compared to in the old (>35 years) group of patients. Our present results underline the potential use of cagE genotyping in the risk assessment of the development of periodontal attachment loss in Swedish adolescents.
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Affiliation(s)
- Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden
| | - Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden
| | - Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden
| | - Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry and Oral Health, Aarhus University, 8000 Aarhus, Denmark
| | - Mark Lindholm
- Division of Oral Microbiology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden
| | - Sarah Jasim
- Division of Oral Microbiology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden
| | - Jan Oscarsson
- Division of Oral Microbiology, Department of Odontology, Umeå University, 907 00 Umeå, Sweden.
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26
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Gómez-Bañuelos E, Mukherjee A, Darrah E, Andrade F. Rheumatoid Arthritis-Associated Mechanisms of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. J Clin Med 2019; 8:jcm8091309. [PMID: 31454946 PMCID: PMC6780899 DOI: 10.3390/jcm8091309] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 12/19/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology characterized by immune-mediated damage of synovial joints and antibodies to citrullinated antigens. Periodontal disease, a bacterial-induced inflammatory disease of the periodontium, is commonly observed in RA and has implicated periodontal pathogens as potential triggers of the disease. In particular, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans have gained interest as microbial candidates involved in RA pathogenesis by inducing the production of citrullinated antigens. Here, we will discuss the clinical and mechanistic evidence surrounding the role of these periodontal bacteria in RA pathogenesis, which highlights a key area for the treatment and preventive interventions in RA.
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Affiliation(s)
- Eduardo Gómez-Bañuelos
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Amarshi Mukherjee
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Erika Darrah
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Felipe Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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27
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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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28
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Jensen AB, Haubek D, Claesson R, Johansson A, Nørskov‐Lauritsen N. Comprehensive antimicrobial susceptibility testing of a large collection of clinical strains ofAggregatibacter actinomycetemcomitansdoes not identify resistance to amoxicillin. J Clin Periodontol 2019; 46:846-854. [DOI: 10.1111/jcpe.13148] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/21/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Anne B. Jensen
- Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
- Department of Clinical Microbiology Aarhus University Hospital Aarhus Denmark
| | - Dorte Haubek
- Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
| | - Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Faculty of Medicine and Odontology Umeå University Umeå Sweden
| | - Anders Johansson
- Division of Periodontology, Department of Odontology, Faculty of Medicine and Odontology Umeå University Umeå Sweden
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29
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Hiyoshi T, Domon H, Maekawa T, Nagai K, Tamura H, Takahashi N, Yonezawa D, Miyoshi T, Yoshida A, Tabeta K, Terao Y. Aggregatibacter actinomycetemcomitans induces detachment and death of human gingival epithelial cells and fibroblasts via elastase release following leukotoxin-dependent neutrophil lysis. Microbiol Immunol 2019; 63:100-110. [PMID: 30817027 DOI: 10.1111/1348-0421.12672] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/09/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022]
Abstract
Aggregatibacter actinomycetemcomitans is considered to be associated with periodontitis. Leukotoxin (LtxA), which destroys leukocytes in humans, is one of this bacterium's major virulence factors. Amounts of neutrophil elastase (NE), which is normally localized in the cytoplasm of neutrophils, are reportedly increased in the saliva of patients with periodontitis. However, the mechanism by which NE is released from human neutrophils and the role of NE in periodontitis is unclear. In the present study, it was hypothesized that LtxA induces NE release from human neutrophils, which subsequently causes the breakdown of periodontal tissues. LtxA-treatment did not induce significant cytotoxicity against human gingival epithelial cells (HGECs) or human gingival fibroblasts (HGFs). However, it did induce significant cytotoxicity against human neutrophils, leading to NE release. Furthermore, NE and the supernatant from LtxA-treated human neutrophils induced detachment and death of HGECs and HGFs, these effects being inhibited by administration of an NE inhibitor, sivelestat. The present results suggest that LtxA mediates human neutrophil lysis and induces the subsequent release of NE, which eventually results in detachment and death of HGECs and HGFs. Thus, LtxA-induced release of NE could cause breakdown of periodontal tissue and thereby exacerbate periodontitis.
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Affiliation(s)
- Takumi Hiyoshi
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Research Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomoki Maekawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Research Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kosuke Nagai
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hikaru Tamura
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Research Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Naoki Takahashi
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Daisuke Yonezawa
- Research Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Division of Oral Science for Health Promotion, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomohiro Miyoshi
- Department of Oral Microbiology, Matsumoto Dental University, Shiojiri, Japan
| | - Akihiro Yoshida
- Department of Oral Microbiology, Matsumoto Dental University, Shiojiri, Japan
| | - Koichi Tabeta
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Research Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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30
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Levy DH, Chapple ILC, Shapira L, Golan-Goldhirsh A, Gopas J, Polak D. Nupharidine enhances Aggregatibacter actinomycetemcomitans clearance by priming neutrophils and augmenting their effector functions. J Clin Periodontol 2018; 46:62-71. [PMID: 30372545 DOI: 10.1111/jcpe.13036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 09/07/2018] [Accepted: 10/21/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Nupharidine (6,6'-Dihydroxythiobinupharidine), purified from the aquatic plant Nuphar lutea leaves (Water lily) prompts antimicrobial activity of immune cells. The aim of the study was to test the effect of Nupharidine on neutrophil function against Aggregatibacter actinomycetemcomitans, JP2 clone (Aa-JP2). METHODS Neutrophils derived from the human cell line HL60 and human peripheral blood derived from aggressive periodontitis and periodontally healthy subjects were incubated with Nupharidine or vehicle and inoculated with JP2. Bacterial survival was tested using viable counts on blood agar (CFU's). Neutrophils' necrosis/apoptosis, reactive oxygen species (ROS) production, phagocytosis and neutrophil extracellular traps (NET) production following infection were tested, as well as markers of neutrophil priming. RESULTS Nupharidine had no direct bactericidal effect on JP2, but it enhanced Aa-JP2 clearance by neutrophils. Nupharidine enhanced neutrophil phagocytosis, ROS production and NET formation during JP2 infection. Furthermore, Nupharidine enhanced the expression of certain markers of neutrophils priming, specifically iCAM1, DECTIN-2 and intracellular IL-1β. CONCLUSION Nupharidine was shown to promote neutrophil effector bactericidal functions, boosting Aa-JP2 clearance. The results point to the potential of Nupharidine as an adjunctive agent in the treatment of Aa-JP2 periodontitis, but this should be tested initially using pre-clinical and clinical studies.
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Affiliation(s)
- Dan Henry Levy
- Department of Microbiology, Immunology and Genetics, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Iain L C Chapple
- Periodontal Research Group, Institute of Clinical Sciences, College of Medical and Dental Sciences, School of Dentistry, University of Birmingham, Birmingham Community Health Trust, Birmingham, UK
| | - Lior Shapira
- Department of Periodontology, The Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Avi Golan-Goldhirsh
- The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Jacob Gopas
- Department of Microbiology, Immunology and Genetics, Ben Gurion University of the Negev, Beer Sheva, Israel.,Department of Oncology, Soroka University Medical Center, Beer Sheva, Israel
| | - David Polak
- Department of Periodontology, The Hebrew University-Hadassah Medical Center, Jerusalem, Israel
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31
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Nygren P, Balashova N, Brown AC, Kieba I, Dhingra A, Boesze-Battaglia K, Lally ET. Aggregatibacter actinomycetemcomitans leukotoxin causes activation of lymphocyte function-associated antigen 1. Cell Microbiol 2018; 21:e12967. [PMID: 30329215 DOI: 10.1111/cmi.12967] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/20/2018] [Accepted: 10/05/2018] [Indexed: 11/29/2022]
Abstract
Repeats-in-toxin leukotoxin (LtxA) produced by the oral bacterium Aggregatibacter actinomycetemcomitans kills human leukocytes in a lymphocyte function-associated antigen 1 (LFA-1, integrin αL /β2 )-dependent manner, although the mechanism for this interaction has not been identified. The LtxA internalisation by LFA-1-expressing cells was explored with florescence resonance energy transfer (FRET) microscopy using a cell line that expresses LFA-1 with a cyan fluorescent protein-tagged cytosolic αL domain and a yellow fluorescent protein-tagged β2 domain. Phorbol 12-myristate 13-acetate activation of LFA-1 caused transient cytosolic domain separation. However, addition of LtxA resulted in an increase in FRET, indicating that LtxA brings the cytosolic domains closer together, compared with the inactive state. Unlike activation, this effect was not transient, lasting more than 30 min. Equilibrium constants of LtxA binding to the cytoplasmic domains of both αL and β2 were determined using surface plasmon resonance. LtxA has a strong affinity for the cytosolic domains of both the αL and β2 subunits (Kd = 15 and 4.2 nM, respectively) and a significantly lower affinity for the cytoplasmic domains of other integrin αM , αX , and β3 subunits (Kd = 400, 180, and 230 nM, respectively), used as controls. Peptide fragments of αL and β2 show that LtxA binds membrane-proximal domain of αL and intermediate domain of β2 .
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Affiliation(s)
- Patrik Nygren
- Departments of Biochemistry, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nataliya Balashova
- Departments of Pathology, School of Dental Medicine, and the Division of Hematology/Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Angela C Brown
- Departments of Pathology, School of Dental Medicine, and the Division of Hematology/Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Irene Kieba
- Departments of Pathology, School of Dental Medicine, and the Division of Hematology/Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anuradha Dhingra
- Departments of Biochemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Edward T Lally
- Departments of Pathology, School of Dental Medicine, and the Division of Hematology/Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
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32
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Mukherjee A, Jantsch V, Khan R, Hartung W, Fischer R, Jantsch J, Ehrenstein B, Konig MF, Andrade F. Rheumatoid Arthritis-Associated Autoimmunity Due to Aggregatibacter actinomycetemcomitans and Its Resolution With Antibiotic Therapy. Front Immunol 2018; 9:2352. [PMID: 30459755 PMCID: PMC6232707 DOI: 10.3389/fimmu.2018.02352] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/24/2018] [Indexed: 11/18/2022] Open
Abstract
Background:Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative coccobacillus recognized as a pathogen in periodontitis and infective endocarditis. By producing a toxin (leukotoxin A, LtxA) that triggers global hypercitrullination in neutrophils, Aa has been recently linked to rheumatoid arthritis (RA) pathogenesis. Although mechanistic and clinical association studies implicate Aa infection in the initiation of autoimmunity in RA, direct evidence in humans is lacking. Case:We describe a 59-year-old man with anti-citrullinated protein antibody (ACPA)-positive RA who presented for evaluation of refractory disease. He was found to have Aa endocarditis. Following antibiotic treatment, joint symptoms resolved and ACPAs normalized. Given the implications for RA immunopathogenesis, we further investigated the bacterial, genetic and immune factors that may have contributed to the patient's clinical and autoimmune phenotypes. Methods:DNA was extracted from serum and used to amplify the Aa leukotoxin (ltx) promoter region by PCR, which was further analyzed by Sanger sequencing. High-resolution identification of HLA alleles was performed by sequenced based typing (SBT). TNF-α, IFN-γ, GM-CSF, IL-1β, IL-6, IL-8, IL-17A, IL-18, IL-21, and IL-22 were quantified in serum by a multiplex immunoassay. IgG and IgA antibodies to Aa LtxA were assayed by ELISA. Results:Aa genotyping confirmed infection with a highly leukotoxic strain carrying a 530-bp ltx promoter deletion, shown to result in 10- to 20-fold higher bacterial expression of LtxA. Immuno-phenotyping showed high anti-LtxA antibodies, elevated cytokines implicated in RA pathogenesis (Th1/Th17), and specific host susceptibility conferred by three HLA alleles strongly linked to ACPAs and RA (DRB1*04:04, DRB1*15:01, and DPB1*04:01). One year after eradication of Aa, the patient remained free of arthritis and anti-CCP antibodies. Conclusion: In the context of genetic risk for RA, systemic subacute infection with a leukotoxic strain of Aa can drive ACPA production and a clinical phenotype similar to RA.
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Affiliation(s)
- Amarshi Mukherjee
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Vanessa Jantsch
- Klinik und Poliklinik für Rheumatologie, Klinische Immunologie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
| | - Rida Khan
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Wolfgang Hartung
- Klinik und Poliklinik für Rheumatologie, Klinische Immunologie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
| | - René Fischer
- Department of Otorhinolaryngology, University Hospital Regensburg, Regensburg, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, Regensburg, Germany
| | - Boris Ehrenstein
- Klinik und Poliklinik für Rheumatologie, Klinische Immunologie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
| | - Maximilian F Konig
- Department of Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Felipe Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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33
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Chung J, Kim S, Lee HA, Park MH, Kim S, Song YR, Na HS. Trans-cinnamic aldehyde inhibitsAggregatibacter actinomycetemcomitans-induced inflammation in THP-1-derived macrophages via autophagy activation. J Periodontol 2018; 89:1262-1271. [DOI: 10.1002/jper.17-0727] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Jin Chung
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Sumi Kim
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Hyun Ah Lee
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Mi Hee Park
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Seyeon Kim
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Yu Ri Song
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
| | - Hee Sam Na
- Department of Oral Microbiology; School of Dentistry; Pusan National University; Yangsan South Korea
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34
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Abdullahi M, Olotu FA, Soliman ME. Solving the riddle: Unraveling the mechanisms of blocking the binding of leukotoxin by therapeutic antagonists in periodontal diseases. J Cell Biochem 2018; 119:9364-9379. [PMID: 30129224 DOI: 10.1002/jcb.27254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacteria that has gained wide recognition for its causative role in the development of various immune diseases, which includes localized aggressive periodontitis. Its ability to evade host defense mechanisms is mediated by the secretion of leukotoxin (LtxA), which induces death of white blood cells (leukocytes) by specific binding to their surface-expressed leukocyte function-associated receptor (LFA-1) in its active state. Therapeutic compounds that interfere with this pathogenic process and abrogate A. actinomycetemcomitans virulence have been reported in literature. These include doxycycline, and more recently phytochemical compounds such as hamamelitanin, resveratrol, naringin, and quercetin. However, the question remains how do they work? Therefore, with the aid of computational tools, we explore the molecular mechanisms by which they possibly elicit their therapeutic functions. Molecular mechanics Poisson/Boltzmann surface area analyses revealed that these compounds bind favorably to active LFA-1 with high affinity and considerable stability, indicative of their ability to occupy the LtxA binding site (LBS) and prevent LtxA binding. The conformational transition of open LFA-1 to its closed state further describe the mechanistic activity of these compounds. In addition to notable reductions in structural mobility and flexibility, the burial of surface-exposed interactive side chains at the LBS was observed, an occurrence that could alter the complementary binding of LtxA. It is also important to mention that these occurrences were induced more prominently by the phytochemicals. We believe that these findings will enhance the scope of drug design and discovery for potent LtxA antagonists with improved activities and therapeutic efficacies in the treatment of virulent A. actinomycetemcomitans diseases.
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Affiliation(s)
- Maryam Abdullahi
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Fisayo A Olotu
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Mahmoud E Soliman
- Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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35
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Balashova N, Giannakakis A, Brown AC, Koufos E, Benz R, Arakawa T, Tang HY, Lally ET. Generation of a recombinant Aggregatibacter actinomycetemcomitans RTX toxin in Escherichia coli. Gene 2018; 672:106-114. [PMID: 29879499 DOI: 10.1016/j.gene.2018.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/28/2018] [Accepted: 06/03/2018] [Indexed: 10/14/2022]
Abstract
A leukotoxin (LtxA) that is produced by Aggregatibacter actinomycetemcomitans (Aa) is an important virulence determinant in an aggressive form of periodontitis in adolescents. Understanding the function of this protein at the molecular level is critical to elucidating its role in the disease process. To accomplish genetic analysis of the protein structure and relating these observations to toxin function, we have developed an E. coli expression system for the generation and rapid purification of LtxA. Cloning the structural toxin gene, ltxA, from Aa strain JP2 under control of T7 promoter-1 of pCDFDuet-1 vector resulted in expression of a 114 KDa protein which could be easily purified by the presence of a carboxy-terminal engineered double hexahistidine (double-His6) tag and was immunologically reactive with an anti-LtxA monoclonal antibody, but was not cytotoxic. Cloning a second gene, ltxC, an acyltransferase gene, into the vector under control of T7 promoter-2, resulted in expression of the biologically active LtxA. The toxin was extracted from E. coli inclusion bodies, purified by immobilized metal affinity chromatography, and refolded by dialysis. When compared by circular dichroism (CD) spectroscopy analysis, acylated recombinant LtxA has a secondary structure consistent with wt LtxA, while variations in α-helical structure of nonacylated LtxA were observed. No modifications in α-helix were found upon the toxin's binding with liposome-incorporated cholesterol. Our results suggest that pure, biologically active recombinant LtxA can be isolated by a one-step affinity chromatography from E. coli. The toxic and structural properties of the recombinant LtxA are similar to its wt counterpart.
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Affiliation(s)
- Nataliya Balashova
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Giannakakis
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Evan Koufos
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Roland Benz
- Department of Life Science and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Tsutomu Arakawa
- Alliance Protein Laboratories, a Division of KBI Biopharma, San Diego, CA, USA
| | - Hsin-Yao Tang
- Proteomics and Metabolomics Facility, The Wistar Institute, Philadelphia, PA, USA
| | - Edward T Lally
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Pietiäinen M, Kopra KAE, Vuorenkoski J, Salminen A, Paju S, Mäntylä P, Buhlin K, Liljestrand JM, Nieminen MS, Sinisalo J, Hyvärinen K, Pussinen PJ. Aggregatibacter actinomycetemcomitansserotypes associate with periodontal and coronary artery disease status. J Clin Periodontol 2018; 45:413-421. [DOI: 10.1111/jcpe.12873] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Milla Pietiäinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - K. A. Elisa Kopra
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Juha Vuorenkoski
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Aino Salminen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Department of Dental Medicine Huddinge; Division of Periodontology; Karolinska Institutet; Huddinge Sweden
| | - Susanna Paju
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Päivi Mäntylä
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Institute of Dentistry; University of Eastern Finland; Kuopio Finland
- Oral and Maxillofacial Diseases; Kuopio University Hospital; Kuopio Finland
| | - Kåre Buhlin
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Department of Dental Medicine Huddinge; Division of Periodontology; Karolinska Institutet; Huddinge Sweden
| | - John M. Liljestrand
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Markku S. Nieminen
- Department of Cardiology, Heart and Lung Center; Helsinki University Hospital; Helsinki Finland
| | - Juha Sinisalo
- Department of Cardiology, Heart and Lung Center; Helsinki University Hospital; Helsinki Finland
| | - Kati Hyvärinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Pirkko J. Pussinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
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Tsai CC, Ho YP, Chou YS, Ho KY, Wu YM, Lin YC. Aggregatibacter (Actinobacillus) actimycetemcomitans leukotoxin and human periodontitis - A historic review with emphasis on JP2. Kaohsiung J Med Sci 2018; 34:186-193. [PMID: 29655406 DOI: 10.1016/j.kjms.2018.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/06/2017] [Accepted: 01/12/2018] [Indexed: 10/18/2022] Open
Abstract
Aggregatibacter (Actinobacillus) actimycetemcomitans (Aa) is a gram-negative bacterium that colonizes the human oral cavity and is causative agent for localized aggressive (juvenile) periodontitis (AgP). In the middle of 1990s, a specific JP2 clone of belonging to the cluster of serotype b strains of Aa with highly leukotoxicity (leukotoxin, LtxA) able to kill human immune cells was isolated. JP2 clone of Aa was strongly associated with in particularly in rapidly progressing forms of aggressive periodontitis. The JP2 clone of Aa is transmitted through close contacts. Therefore, AgP patients need intense monitoring of their periodontal status as the risk for developing severely progressing periodontitis lesions are relatively high. Furthermore, timely periodontal treatment, including periodontal surgery supplemented by the use of antibiotics, is warranted. More importantly, periodontal attachment loss should be prevented by early detection of the JP2 clone of Aa by microbial diagnosis testing and/or preventive means.
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Affiliation(s)
- Chi-Cheng Tsai
- School of Dentistry, College of Oral Medicine, University Hospital, Chung Shan Medical University, Taichung City, Taiwan.
| | - Ya-Ping Ho
- College of Dental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Periodontics, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Yu-Shian Chou
- Division of Periodontics, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Kun-Yen Ho
- College of Dental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Periodontics, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Yi-Min Wu
- College of Dental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan; Division of Periodontics, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Ying-Chu Lin
- College of Dental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
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Konig MF, Abusleme L, Reinholdt J, Palmer RJ, Teles RP, Sampson K, Rosen A, Nigrovic PA, Sokolove J, Giles JT, Moutsopoulos NM, Andrade F. Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis. Sci Transl Med 2017; 8:369ra176. [PMID: 27974664 DOI: 10.1126/scitranslmed.aaj1921] [Citation(s) in RCA: 355] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 09/09/2016] [Accepted: 11/09/2016] [Indexed: 12/16/2022]
Abstract
A bacterial etiology of rheumatoid arthritis (RA) has been suspected since the beginnings of modern germ theory. Recent studies implicate mucosal surfaces as sites of disease initiation. The common occurrence of periodontal dysbiosis in RA suggests that oral pathogens may trigger the production of disease-specific autoantibodies and arthritis in susceptible individuals. We used mass spectrometry to define the microbial composition and antigenic repertoire of gingival crevicular fluid in patients with periodontal disease and healthy controls. Periodontitis was characterized by the presence of citrullinated autoantigens that are primary immune targets in RA. The citrullinome in periodontitis mirrored patterns of hypercitrullination observed in the rheumatoid joint, implicating this mucosal site in RA pathogenesis. Proteomic signatures of several microbial species were detected in hypercitrullinated periodontitis samples. Among these, Aggregatibacter actinomycetemcomitans (Aa), but not other candidate pathogens, induced hypercitrullination in host neutrophils. We identified the pore-forming toxin leukotoxin A (LtxA) as the molecular mechanism by which Aa triggers dysregulated activation of citrullinating enzymes in neutrophils, mimicking membranolytic pathways that sustain autoantigen citrullination in the RA joint. Moreover, LtxA induced changes in neutrophil morphology mimicking extracellular trap formation, thereby releasing the hypercitrullinated cargo. Exposure to leukotoxic Aa strains was confirmed in patients with RA and was associated with both anticitrullinated protein antibodies and rheumatoid factor. The effect of human lymphocyte antigen-DRB1 shared epitope alleles on autoantibody positivity was limited to RA patients who were exposed to Aa These studies identify the periodontal pathogen Aa as a candidate bacterial trigger of autoimmunity in RA.
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Affiliation(s)
- Maximilian F Konig
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Loreto Abusleme
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jesper Reinholdt
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | - Robert J Palmer
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ricardo P Teles
- Department of Periodontology, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA 02142, USA
| | - Kevon Sampson
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Antony Rosen
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Peter A Nigrovic
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA.,Division of Immunology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jeremy Sokolove
- Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jon T Giles
- Division of Rheumatology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Niki M Moutsopoulos
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Felipe Andrade
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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Fekrazad R, Khoei F, Bahador A, Hakimiha N. Photo-activated elimination of Aggregatibacter actinomycetemcomitans in planktonic culture: Comparison of photodynamic therapy versus photothermal therapy method. Photodiagnosis Photodyn Ther 2017; 19:28-32. [DOI: 10.1016/j.pdpdt.2017.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 01/10/2023]
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40
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Claesson R, Höglund-Åberg C, Haubek D, Johansson A. Age-related prevalence and characteristics of Aggregatibacter actinomycetemcomitans in periodontitis patients living in Sweden. J Oral Microbiol 2017; 9:1334504. [PMID: 28748039 PMCID: PMC5508378 DOI: 10.1080/20002297.2017.1334504] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/11/2017] [Indexed: 02/08/2023] Open
Abstract
Background: The presence of Aggregatibacter actinomycetemcomitans in patients with periodontitis has been extensively studied for decades. Objective: To study the prevalence of A. actinomycetemcomitans in younger and older periodontitis patients and to genetically characterize isolates of this bacterium. Design: Data from microbiological analyses of 3459 subgingival plaque samples collected from 1445 patients, 337 ‘younger’ patients (≤35 yrs) and 1108 ‘older’ patients (>35 yrs) during 15 years (2000–2014), has been summerized. Isolates of A. actinomycetemcomitans were serotyped, leukotoxin promoter typed (JP2 and non JP2) and arbitrarily primed PCR (AP-PCR) genotyped. The origin of the JP2 genotype detected in the study population was determined. Results: The prevalence of A. actinomycetemcomitans was higher among younger than older patients and samples from the younger patients contained higher proportions of the bacterium. Serotype b was more prevalent among younger patients and the majorty of these isolates was from the same AP-PCR genotype. The JP2 genotype was detected in 1.2% of the patients, and the majority of these carriers were of non-African origin. Conslusions: For presence and charcteristics of A. actinomycetemcomitans in clinical samples the age of the carriers were a discriminating factor. Additional, apparently non-African carriers of the JP2 genotype of A. actinomycetemcomitans were identified.
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Affiliation(s)
- Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Carola Höglund-Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry, Health, Aarhus UniversityAarhus, Denmark
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
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41
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Johansson A, Claesson R, Höglund Åberg C, Haubek D, Oscarsson J. ThecagEgene sequence as a diagnostic marker to identify JP2 and non-JP2 highly leukotoxicAggregatibacter actinomycetemcomitansserotype b strains. J Periodontal Res 2017; 52:903-912. [DOI: 10.1111/jre.12462] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2017] [Indexed: 12/27/2022]
Affiliation(s)
- A. Johansson
- Division of Molecular Periodontology; Department of Odontology; Umeå University; Umeå Sweden
| | - R. Claesson
- Division of Oral Microbiology; Department of Odontology; Umeå University; Umeå Sweden
| | - C. Höglund Åberg
- Division of Molecular Periodontology; Department of Odontology; Umeå University; Umeå Sweden
| | - D. Haubek
- Section for Pediatric Dentistry; Department of Dentistry and Oral Health; Aarhus University; Aarhus Denmark
| | - J. Oscarsson
- Division of Oral Microbiology; Department of Odontology; Umeå University; Umeå Sweden
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Johansson A, Buhlin K, Sorsa T, Pussinen PJ. Systemic Aggregatibacter actinomycetemcomitans Leukotoxin-Neutralizing Antibodies in Periodontitis. J Periodontol 2017; 88:122-129. [DOI: 10.1902/jop.2016.160193] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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43
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Hirschfeld J, Roberts HM, Chapple ILC, Parčina M, Jepsen S, Johansson A, Claesson R. Effects of Aggregatibacter actinomycetemcomitans leukotoxin on neutrophil migration and extracellular trap formation. J Oral Microbiol 2016; 8:33070. [PMID: 27834173 PMCID: PMC5103672 DOI: 10.3402/jom.v8.33070] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 09/26/2016] [Accepted: 10/04/2016] [Indexed: 12/12/2022] Open
Abstract
Background Aggressive periodontitis is associated with the presence of Aggregatibacter actinomycetemcomitans, a leukotoxin (Ltx)-producing periodontal pathogen. Ltx has the ability to lyse white blood cells including neutrophils. Objectives This study was aimed at investigating the interactions between neutrophils and Ltx with regard to the chemotactic properties of Ltx and the release of neutrophil extracellular traps (NETs). Methods Neutrophils from healthy blood donors were isolated and incubated for 30 min and 3 h with increasing concentrations of Ltx (1, 10, and 100 ng/mL) as well as with A. actinomycetemcomitans strains (NCTC 9710 and HK 1651) producing different levels of Ltx. Formation of NETs and cell lysis were assessed by microscopy, fluorescence-based assays, and measurement of released lactate dehydrogenase. Neutrophil migration in response to different Ltx gradients was monitored by real-time video microscopy, and image analysis was performed using ImageJ software. Results Although Ltx (10 and 100 ng/mL) and the leukotoxic A. actinomycetemcomitans strain HK 1651 lysed some neutrophils, other cells were still capable of performing NETosis in a concentration-dependent manner. Low doses of Ltx and the weakly leukotoxic strain NCTC 9710 did not lead to neutrophil lysis, but did induce some NETosis. Furthermore, all three concentrations of Ltx enhanced random neutrophil movement; however, low directional accuracy was observed compared with the positive control (fMLP). Conclusions The results indicate that Ltx acts both as a neutrophil activator and also causes cell death. In addition, Ltx directly induces NETosis in neutrophils prior to cell lysis. In future studies, the underlying pathways involved in Ltx-meditated neutrophil activation and NETosis need to be investigated further.
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Affiliation(s)
- Josefine Hirschfeld
- Periodontal Research Group, Birmingham Dental School & Hospital, Birmingham, United Kingdom.,Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Bonn, Germany;
| | - Helen M Roberts
- Periodontal Research Group, Birmingham Dental School & Hospital, Birmingham, United Kingdom
| | - Iain L C Chapple
- Periodontal Research Group, Birmingham Dental School & Hospital, Birmingham, United Kingdom
| | - Marijo Parčina
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Søren Jepsen
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Bonn, Germany
| | - Anders Johansson
- Section Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Rolf Claesson
- Section Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
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Damgaard C, Reinholdt J, Palarasah Y, Enevold C, Nielsen C, Brimnes MK, Holmstrup P, Nielsen CH. In vitro complement activation, adherence to red blood cells and induction of mononuclear cell cytokine production by four strains of Aggregatibacter actinomycetemcomitans with different fimbriation and expression of leukotoxin. J Periodontal Res 2016; 52:485-496. [PMID: 27663487 DOI: 10.1111/jre.12414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2016] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND OBJECTIVE The periodontal pathogen Aggregatibacter actinomycetemcomitans has been proposed as pro-atherogenic, and complement-mediated adherence to red blood cells (RBCs) may facilitate its systemic spread. We investigated the ability of four strains of A. actinomycetemcomitans with differential expression of leukotoxin A (LtxA) and fimbriae to activate complement, adhere to RBCs and elicit cytokine responses by mononuclear cells (MNCs). MATERIAL AND METHODS Aggregatibacter actinomycetemcomitans serotype b strains HK 921, HK 1651, HK 2092 and HK 2108 were fluorescence-labeled, incubated with human whole blood cells in the presence of autologous serum, and assessed for RBC adherence by flow cytometry and for capacity to induce cytokine production by cytometric bead array analysis. The levels of IgG to A. actinomycetemcomitans serotype b were quantified by ELISA, as was consumption of complement. RESULTS The JP2 clone variants HK 1651 and, to a lesser extent, HK 2092, consumed complement efficiently, while HK 2108 (= strain Y4) consumed complement poorly. Nonetheless, the four tested strains adhered equally well to RBCs in the presence of autologous serum, without causing RBC lysis. The JP2 clone variant HK 2092, selectively lacking LtxA production, induced higher production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 by MNCs than did the other three strains, while the four strains induced similar production of IL-12p70. RBCs facilitated the HK 2092-induced production of TNF-α and IL-1β, and IL-6 was enhanced by RBCs, and this facilitation could be counteracted by blockade of complement receptor 3 (CD11b/CD18). CONCLUSION Our data suggest that the JP2 clone of A. actinomycetemcomitans, most closely resembled by the variant HK 1651, activates complement well, while strain Y4, represented by HK 2108, activates complement poorly. However, all strains of A. actinomycetemcomitans adhere to RBCs and, when capable of producing LtxA, prevent production of inflammatory cytokines by MNCs. This "immunologically silent" immune adherence may facilitate systemic spread and atherogenesis.
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Affiliation(s)
- C Damgaard
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - J Reinholdt
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Y Palarasah
- Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark
| | - C Enevold
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - C Nielsen
- Department of Clinical Immunology, Odense University Hospital, Odense, Denmark
| | - M K Brimnes
- Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - P Holmstrup
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - C H Nielsen
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Velusamy SK, Sampathkumar V, Godboley D, Fine DH. Profound Effects of Aggregatibacter actinomycetemcomitans Leukotoxin Mutation on Adherence Properties Are Clarified in in vitro Experiments. PLoS One 2016; 11:e0151361. [PMID: 26977924 PMCID: PMC4792451 DOI: 10.1371/journal.pone.0151361] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/27/2016] [Indexed: 02/02/2023] Open
Abstract
Leukotoxin (Ltx) is a prominent virulence factor produced by Aggregatibacter actinomycetemcomitans, an oral microorganism highly associated with aggressive periodontitis. Ltx compromises host responsiveness by altering the viability of neutrophils, lymphocytes, and macrophages. Previously, we developed a Rhesus (Rh) monkey colonization model designed to determine the effect of virulence gene mutations on colonization of A. actinomycetemcomitans. Unexpectedly, an A. actinomycetemcomitans leukotoxin (ltxA) mutant (RhAa-VS2) failed to colonize in the Rh model. No previous literature suggested that Ltx was associated with A. actinomycetemcomitans binding to tooth surfaces. These results led us to explore the broad effects of the ltxA mutation in vitro. Results indicated that LtxA activity was completely abolished in RhAa-VS2 strain, while complementation significantly (P<0.0001) restored leukotoxicity compared to RhAa-VS2 strain. RT-PCR analysis of ltx gene expression ruled out polar effects. Furthermore, binding of RhAa-VS2 to salivary-coated hydroxyapatite (SHA) was significantly decreased (P<0.0001) compared to wild type RhAa3 strain. Real time RT-PCR analysis of the genes related to SHA binding in RhAa-VS2 showed that genes related to binding were downregulated [rcpA (P = 0.018), rcpB (P = 0.02), tadA (P = 0.002)] as compared to wild type RhAa3. RhAa-VS2 also exhibited decreased biofilm depth (P = 0.008) and exo-polysaccharide production (P<0.0001). Buccal epithelial cell (BEC) binding of RhAa-VS2 was unaffected. Complementation with ltxA restored binding to SHA (P<0.002) but had no effect on biofilm formation when compared to RhAa3. In conclusion, mutation of ltxA diminished hard tissue binding in vitro, which helps explain the previous in vivo failure of a ltxA knockout to colonize the Rh oral cavity. These results suggest that; 1) one specific gene knockout (in this case ltxA) could affect other seemingly unrelated genes (such as rcpA, rcpB tadA etc), and 2) some caution should be used when interpreting the effect attributed to targeted gene mutations when seen in a competitive in vivo environment.
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Affiliation(s)
- Senthil Kumar Velusamy
- Department of Oral Biology, Rutgers School of Dental Medicine, 185 South Orange Ave, Newark, New Jersey, United States of America
| | - Vandana Sampathkumar
- Department of Oral Biology, Rutgers School of Dental Medicine, 185 South Orange Ave, Newark, New Jersey, United States of America
| | - Dipti Godboley
- Department of Oral Biology, Rutgers School of Dental Medicine, 185 South Orange Ave, Newark, New Jersey, United States of America
| | - Daniel H. Fine
- Department of Oral Biology, Rutgers School of Dental Medicine, 185 South Orange Ave, Newark, New Jersey, United States of America
- * E-mail:
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46
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Jensen AB, Ennibi OK, Ismaili Z, Poulsen K, Haubek D. The JP2 genotype of Aggregatibacter actinomycetemcomitans
and marginal periodontitis in the mixed dentition. J Clin Periodontol 2016; 43:19-25. [PMID: 26659719 DOI: 10.1111/jcpe.12486] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2015] [Indexed: 10/25/2022]
Affiliation(s)
- Anne Birkeholm Jensen
- Section for Pediatric Dentistry; Department of Dentistry, Health; Aarhus University; Aarhus Denmark
| | - Oum Keltoum Ennibi
- Department of Periodontology; Faculty of Medicine Dentistry; Mohammed V Souissi University; Rabat Morocco
| | - Zouheir Ismaili
- Department of Periodontology; Faculty of Medicine Dentistry; Mohammed V Souissi University; Rabat Morocco
| | - Knud Poulsen
- Department of Biomedicine, Health; Aarhus University; Aarhus Denmark
| | - Dorte Haubek
- Section for Pediatric Dentistry; Department of Dentistry, Health; Aarhus University; Aarhus Denmark
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47
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Åberg CH, Kelk P, Johansson A. Aggregatibacter actinomycetemcomitans: virulence of its leukotoxin and association with aggressive periodontitis. Virulence 2016; 6:188-95. [PMID: 25494963 PMCID: PMC4601274 DOI: 10.4161/21505594.2014.982428] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Periodontitis is an infection-induced inflammatory disease that causes loss of the tooth supporting tissues. Much focus has been put on comparison of the microbial biofilm in the healthy periodontium with the diseased one. The information arising from such studies is limited due to difficulties to compare the microbial composition in these two completely different ecological niches. A few longitudinal studies have contributed with information that makes it possible to predict which individuals who might have an increased risk of developing aggressive forms of periodontitis, and the predictors are either microbial or/and host-derived factors. The most conspicuous condition that is associated with disease risk is the presence of Aggregatibacter actinomycetemcomitans at the individual level. This Gram-negative bacterium has a great genetic variation with a number of virulence factors. In this review we focus in particular on the leukotoxin that, based on resent knowledge, might be one of the most important virulence factors of A. actinomycetemcomitans.
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Affiliation(s)
- Carola Höglund Åberg
- a Division of Molecular Periodontology; Department of Odontology; Faculty of Medicine; Umeå University ; Umeå , Sweden
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Abstract
A paradigm shift several decades ago elucidated that aggressive periodontitis (AgP) was not a degenerative disorder but a rapid progressive form of plaque-induced inflammatory periodontal disease. Ensuing years of research have led to linkage analysis identification of specific genetic defects responsible for AgP in some families and to the finding that subgingival detection of A. actinomycet-emcomitans JP2 clone is a predictive factor for disease onset and progression. However, rather disappointingly, these ‘proven’ risk factors are only detected in a small subset of AgP cases. Recent advances are leading to a new paradigm shift, with the realization that genetically-driven dysbiotic changes in the subgingival microbiota may predispose to a cascade of events leading to the rapid periodontal tissue destruction seen in AgP. This review tries to dissect the existing literature on the host response-microbial axis of AgP and to propose possible pathogenic pathways in line with current theories.
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Affiliation(s)
- Luigi Nibali
- a Periodontology Unit and Department of Clinical Research; UCL Eastman Dental Institute ; London , UK
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Kieselbach T, Zijnge V, Granström E, Oscarsson J. Proteomics of Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles. PLoS One 2015; 10:e0138591. [PMID: 26381655 PMCID: PMC4575117 DOI: 10.1371/journal.pone.0138591] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 09/01/2015] [Indexed: 11/18/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. Outer membrane vesicles (OMVs) released by this species have been demonstrated to deliver effector proteins such as cytolethal distending toxin (CDT) and leukotoxin (LtxA) into human host cells and to act as triggers of innate immunity upon carriage of NOD1- and NOD2-active pathogen-associated molecular patterns (PAMPs). To improve our understanding of the pathogenicity-associated functions that A. actinomycetemcomitans exports via OMVs, we studied the proteome of density gradient-purified OMVs from a rough-colony type clinical isolate, strain 173 (serotype e) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This analysis yielded the identification of 151 proteins, which were found in at least three out of four independent experiments. Data are available via ProteomeXchange with identifier PXD002509. Through this study, we not only confirmed the vesicle-associated release of LtxA, and the presence of proteins, which are known to act as immunoreactive antigens in the human host, but we also identified numerous additional putative virulence-related proteins in the A. actinomycetemcomitans OMV proteome. The known and putative functions of these proteins include immune evasion, drug targeting, and iron/nutrient acquisition. In summary, our findings are consistent with an OMV-associated proteome that exhibits several offensive and defensive functions, and they provide a comprehensive basis to further disclose roles of A. actinomycetemcomitans OMVs in periodontal and systemic disease.
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Affiliation(s)
| | - Vincent Zijnge
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
- * E-mail:
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Claesson R, Gudmundson J, Åberg CH, Haubek D, Johansson A. Detection of a 640-bp deletion in the Aggregatibacter actinomycetemcomitans leukotoxin promoter region in isolates from an adolescent of Ethiopian origin. J Oral Microbiol 2015; 7:26974. [PMID: 25881573 PMCID: PMC4400299 DOI: 10.3402/jom.v7.26974] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 03/03/2015] [Accepted: 03/10/2015] [Indexed: 11/17/2022] Open
Abstract
The expression of the leukotoxin of Aggregatibacter actinomycetemcomitans is regulated by the leukotoxin promoter. A 530-bp deletion or an 886-bp insertion sequence (IS) element in this region has earlier been described in highly leukotoxic isolates. Here, we report on highly leukotoxic isolate with a 640-bp deletion, which was detected in an adolescent of Ethiopian origin.
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Affiliation(s)
- Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden;
| | - Jan Gudmundson
- Periodontology Specialist Clinic, Östersunds Hospital, Östersund, Sweden
| | - Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus, Denmark
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden
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