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Shenker BJ, Korostoff J, Walker LP, Zekavat A, Dhingra A, Kim TJ, Boesze-Battaglia K. Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Induces Cellugyrin-(Synaptogyrin 2) Dependent Cellular Senescence in Oral Keratinocytes. Pathogens 2024; 13:155. [PMID: 38392893 PMCID: PMC10892517 DOI: 10.3390/pathogens13020155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Recently, we reported that oral-epithelial cells (OE) are unique in their response to Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) in that cell cycle arrest (G2/M) occurs without leading to apoptosis. We now demonstrate that Cdt-induced cell cycle arrest in OE has a duration of at least 7 days with no change in viability. Moreover, toxin-treated OE develops a new phenotype consistent with cellular senescence; this includes increased senescence-associated β-galactosidase (SA-β-gal) activity and accumulation of the lipopigment, lipofuscin. Moreover, the cells exhibit a secretory profile associated with cellular senescence known as the senescence-associated secretory phenotype (SASP), which includes IL-6, IL-8 and RANKL. Another unique feature of Cdt-induced OE senescence is disruption of barrier function, as shown by loss of transepithelial electrical resistance and confocal microscopic assessment of primary gingival keratinocyte structure. Finally, we demonstrate that Cdt-induced senescence is dependent upon the host cell protein cellugyrin, a homologue of the synaptic vesicle protein synaptogyrin. Collectively, these observations point to a novel pathogenic outcome in oral epithelium that we propose contributes to both A. actinomycetemcomitans infection and periodontal disease progression.
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Affiliation(s)
- Bruce J. Shenker
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (L.P.W.); (A.Z.); (A.D.); (K.B.-B.)
| | - Jonathan Korostoff
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.K.); (T.J.K.)
| | - Lisa P. Walker
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (L.P.W.); (A.Z.); (A.D.); (K.B.-B.)
| | - Ali Zekavat
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (L.P.W.); (A.Z.); (A.D.); (K.B.-B.)
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (L.P.W.); (A.Z.); (A.D.); (K.B.-B.)
| | - Taewan J. Kim
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.K.); (T.J.K.)
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (L.P.W.); (A.Z.); (A.D.); (K.B.-B.)
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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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Carriage of the JP2 Genotype of Aggregatibacter actinomycetemcomitans by Periodontitis Patients of Various Geographic Origin, Living in Sweden. Pathogens 2022; 11:pathogens11111233. [PMID: 36364984 PMCID: PMC9697931 DOI: 10.3390/pathogens11111233] [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: 09/23/2022] [Revised: 10/14/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
The JP2 genotype of Aggregatibacter actinomycetemcomitans serotype b is associated with aggressive forms of periodontitis and was initially identified as affecting adolescents in North and West Africa. The dissemination of this genotype follows the migration routes and can today be detected in samples from periodontitis patients in a high number of countries. In the present study, we aim to describe findings of the JP2 genotype A. actinomycetemcomits in a clinical laboratory at the Dental School, Odontology, Umeå University, Sweden. The findings of JP2 carriers are documented during a 21-year period, and the age and geographic origin of the sampled individuals are described. In addition, the collected JP2 isolates were separated into North or West African origin by analyses of the presence of a point mutation in the hbpA2 pseudogene of the bacterium. In a total of 2296 sampled individuals during this period in this Swedish population of periodontitis patients, 32 JP2 carriers were detected by cultivation and PCR. The geographic background of these individuals was diverse, including sixteen with African origin, ten with a Swedish origin and six additional ones with a non-African origin. The JP2 genotypes of A. actinomycetemcomitans were mainly isolated from young individuals (<35 years of age), and seven out of the 32 isolates were of a West African origin based on the sequence of hbpA2. We conclude that the JP2 genotype of A. actinomycetemcomitans can be detected world-wide in subgingival plaque samples from adolescents affected by periodontitis.
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Ozuna H, Snider I, Belibasakis GN, Oscarsson J, Johansson A, Uriarte SM. Aggregatibacter actinomycetemcomitans and Filifactor alocis: Two exotoxin-producing oral pathogens. FRONTIERS IN ORAL HEALTH 2022; 3:981343. [PMID: 36046121 PMCID: PMC9420871 DOI: 10.3389/froh.2022.981343] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/27/2022] [Indexed: 12/22/2022] Open
Abstract
Periodontitis is a dysbiotic disease caused by the interplay between the microbial ecosystem present in the disease with the dysregulated host immune response. The disease-associated microbial community is formed by the presence of established oral pathogens like Aggregatibacter actinomycetemcomitans as well as by newly dominant species like Filifactor alocis. These two oral pathogens prevail and grow within the periodontal pocket which highlights their ability to evade the host immune response. This review focuses on the virulence factors and potential pathogenicity of both oral pathogens in periodontitis, accentuating the recent description of F. alocis virulence factors, including the presence of an exotoxin, and comparing them with the defined factors associated with A. actinomycetemcomitans. In the disease setting, possible synergistic and/or mutualistic interactions among both oral pathogens might contribute to disease progression.
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Affiliation(s)
- Hazel Ozuna
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Ian Snider
- Department of Biology, School of Arts and Sciences, University of Louisville, Louisville, KY, United States
| | | | - Jan Oscarsson
- Department of Odontology, Umeå University, Umeå, Sweden
| | | | - Silvia M. Uriarte
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States,*Correspondence: Silvia M. Uriarte
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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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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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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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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: 28] [Impact Index Per Article: 5.6] [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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Ahlstrand T, Kovesjoki L, Maula T, Oscarsson J, Ihalin R. Aggregatibacter actinomycetemcomitans LPS binds human interleukin-8. J Oral Microbiol 2018; 11:1549931. [PMID: 34917288 PMCID: PMC8670607 DOI: 10.1080/20002297.2018.1549931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Various gram-negative species sequester host cytokines using outer membrane proteins or surface modulation by sulfated polysaccharides. An outer membrane lipoprotein (BilRI) of the periodontal pathogen Aggregatibacter actinomycetemcomitans binds several cytokines, including interleukin (IL)-8. Because IL-8 is positively charged at physiological pH, we aimed to determine whether IL-8 interacts with negatively charged lipopolysaccharide (LPS). Binding was investigated using electrophoretic mobility shift assays and microwell-based time-resolved fluorometric immunoassay. LPS from each tested strain of A. actinomycetemcomitans (N = 13), Pseudomonas aeruginosa (N = 1) and Escherichia coli (N = 1) bound IL-8. The Kd value of the A. actinomycetemcomitans LPS-IL-8 interaction varied between 1.2–17 μM irrespective of the serotype and the amount of phosphorus in LPS and was significantly lower than that of the BilRI-IL-8 interaction. Moreover, IL-8 interacted with whole A. actinomycetemcomitans cells and outer membrane vesicles. Hence, LPS might be involved in binding of IL-8 to the outer membrane of A. actinomycetemcomitans. This raises an interesting question regarding whether other gram-negative periodontal pathogens use LPS for IL-8 sequestering in vivo.
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Affiliation(s)
- Tuuli Ahlstrand
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Laura Kovesjoki
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Terhi Maula
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Riikka Ihalin
- Department of Biochemistry, University of Turku, Turku, Finland
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Fawzy El-Sayed K, Graetz C, Köhnlein T, Mekhemar M, Dörfer C. Effect of total sonicated Aggregatibacter actinomycetemcomitans fragments on gingival stem/progenitor cells. Med Oral Patol Oral Cir Bucal 2018; 23:e569-e578. [PMID: 30148477 PMCID: PMC6167108 DOI: 10.4317/medoral.22661] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 08/16/2018] [Indexed: 01/24/2023] Open
Abstract
Background Aggregatibacter-actinomycetemcomitans (A.actinomycetemcomitans) are strongly associated with localized-aggressive-periodontitis (LAgP). The study’s aim was to test for the first time the effect of total sonicated A.actinomycetemcomitans-bacterial-fragments on gingival mesenchymal stem/progenitor cells’ (G-MSCs) proliferation and regenerative gene expression in-vitro. Material and Methods G-MSCs were isolated, characterized, expanded and stimulated by total sonicated A.actinomycetemcomitans-bacterial-fragments (0 (negative-control), 15, 60, 120 and 240µg/ml; serovar-b; n=6/group). Cellular proliferation and NF-κβ (NFKB1), Alkaline Phosphatase (ALPL), Collagen-I (COL1A1), Collagen-III (COL3A1), Osteonectin (SPARC) and Osteopontin (SPP1) m-RNA expression were assessed via reverse-transcription-polymerase-chain-reaction (RT-PCR) at 24, 48 and 72 hours and CFUs-ability evaluated at twelve days. Results G-MSCs demonstrated stem/progenitor cells’ characteristics. A.actinomycetemcomitans-bacterial-fragments (up to 72 hours) resulted in marked G-MSCs’ proliferation over-time (p<0.001) and elevated NFKB1 (p=0.017), COL1A1 (p=0.025), SPARC (p=0.025), decreased ALPL (p=0.017), with no significant differences for COL3A1 and SPP1 expression or stimulation times (p>0.05; Friedman-test). Longer-term stimulation for twelve days reduced G-MSCs’ CFUs. Conclusions Sonicated A.actinomycetemcomitans-bacterial-fragments’ exert beneficial short-term effects on G-MSCs’ proliferative and non-mineralized tissue forming aptitude. Results shed new light on the importance of periodontal treatment for LAgP patients, using power driven sonic/ultrasonic devices, which, in addition to reducing the subgingival microbial load, produces cell-stimulatory A.actinomycetemcomitans-bacterial-fragments, with positive attributes on tissue reparative/regenerative responses of tissue resident stem/progenitor cells in their niche. Key words:Ultrasonic, Aggregatibacter actinomycetemcomitans, stem cells, gingiva, Aggressive periodontitis.
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Affiliation(s)
- K Fawzy El-Sayed
- Clinic for Conservative Dentistry and Periodontology, School of Dental Medicine, Christian Albrechts-Universität zu Kiel, Arnold-Heller-Str. 3, Haus 26, 24105 Kiel, Germany,
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Suprith SS, Setty S, Bhat K, Thakur S. Serotypes of Aggregatibacter actinomycetemcomitans in relation to periodontal status and assessment of leukotoxin in periodontal disease: A clinico-microbiological study. J Indian Soc Periodontol 2018; 22:201-208. [PMID: 29962698 PMCID: PMC6009160 DOI: 10.4103/jisp.jisp_36_18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Context: Aggregatibacter actinomycetemcomitans (A.a) serotypes may add some important information of the pathogenetic background of periodontal infections. A.a leukotoxin is an important virulence factor in the pathogenesis of periodontal disease and its rate of progression. When compared to minimally leukotoxic strains, variants of A.a highly leukotoxic strains produce 10–20 times more leukotoxin. Aims: The aim of the present study was to detect serotypes a, b, c, d, and e of A.a its leukotoxin and find its correlation with periodontal status. Settings and Design: Microbiological analysis and cross-sectional study. Materials and Methods: A total of 80 subjects (40 chronic periodontitis and 40 aggressive periodontitis) in the age range of 14–55 years were selected. Subgingival plaque samples were collected and checked for the presence of A.a. Following isolation of the organism, detection of the serotypes and leukotoxin assessment was done. Statistical Analysis Used: The proportions of A.a were calculated using descriptive statistics in terms of percentage. Chi-square test was used to find association between serotype, leukotoxin, and periodontal disease in individual group. Results: Out of 80 plaque samples, 45% tested positive for A.a. serotype b was detected in 33.33%, whereas serotype e in 8.33% samples and serotype c in 2.77% samples. Serotypes a and d were not detected in any of the samples. A combination of serotypes was seen in 47.22% of the sites. Of these 76.47% showed a combination of 2 serotypes, while 23.52%showed a combination of 3 serotypes. 8.33% showed untypable serotype. All samples had low-toxic variants of A.a. Conclusions: Serotype b and serotype e were predominant in chronic periodontitis, and serotype b was predominant in aggressive periodontitis. An association could be present between serotype and periodontal disease.
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Affiliation(s)
| | - Swati Setty
- Department of Periodontics, SDM College of Dental Sciences and Hospital, Dharwad, Karnataka, India
| | - Kishore Bhat
- Department of Microbiology, Maratha Mandals Nathajirao G. Halgekar Institute of Dental Sciences and Research Centre, Belagavi, Karnataka, India
| | - Srinath Thakur
- Department of Periodontics, SDM College of Dental Sciences and Hospital, Dharwad, Karnataka, India
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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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Kieselbach T, Oscarsson J. Dataset of the proteome of purified outer membrane vesicles from the human pathogen Aggregatibacter actinomycetemcomintans. Data Brief 2016; 10:426-431. [PMID: 28050585 PMCID: PMC5192097 DOI: 10.1016/j.dib.2016.12.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/08/2016] [Indexed: 02/07/2023] Open
Abstract
The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen, which is linked to aggressive forms of periodontitis and can be associated with endocarditis. The outer membrane vesicles (OMVs) of this species contain effector proteins such as cytolethal distending toxin (CDT) and leukotoxin (LtxA), which they can deliver into human host cells. The OMVs can also activate innate immunity through NOD1- and NOD2-active pathogen-associated molecular patterns. This dataset provides a proteome of highly purified OMVs from A. actinomycetemcomitans serotype e strain 173. The experimental data do not only include the raw data of the LC-MS/MS analysis of four independent preparations of purified OMVs but also the mass lists of the processed data and the Mascot.dat files from the database searches. In total 501 proteins are identified, of which 151 are detected in at least three of four independent preparations. In addition, this dataset contains the COG definitions and the predicted subcellular locations (PSORTb 3.0) for the entire genome of A. actinomycetemcomitans serotype e strain SC1083, which is used for the evaluation of the LC-MS/MS data. These data are deposited in ProteomeXchange in the public dataset PXD002509. In addition, a scientific interpretation of this dataset by Kieselbach et al. (2015) [2] is available at http://dx.doi.org/10.1371/journal.pone.0138591.
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Affiliation(s)
- Thomas Kieselbach
- Department of Chemistry, Umeå University, Umeå, Sweden
- Corresponding author.
| | - Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
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Obradović D, Gašperšič R, Caserman S, Leonardi A, Jamnik M, Podlesek Z, Seme K, Anderluh G, Križaj I, Maček P, Butala M. A Cytolethal Distending Toxin Variant from Aggregatibacter actinomycetemcomitans with an Aberrant CdtB That Lacks the Conserved Catalytic Histidine 160. PLoS One 2016; 11:e0159231. [PMID: 27414641 PMCID: PMC4945079 DOI: 10.1371/journal.pone.0159231] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/29/2016] [Indexed: 12/19/2022] Open
Abstract
The periodontopathogen Aggregatibacter actinomycetemcomitans synthesizes several virulence factors, including cytolethal distending toxin (CDT). The active CDT holoenzyme is an AB-type tripartite genotoxin that affects eukaryotic cells. Subunits CdtA and CdtC (B-components) allow binding and intracellular translocation of the active CdtB (A-component), which elicits nuclear DNA damage. Different strains of A. actinomycetemcomitans have diverse virulence genotypes, which results in varied pathogenic potential and disease progression. Here, we identified an A. actinomycetemcomitans strain isolated from two patients with advance chronic periodontitis that has a regular cdtABC operon, which, however, codes for a unique, shorter, variant of the CdtB subunit. We describe the characteristics of this CdtBΔ116–188, which lacks the intact nuclear localisation signal and the catalytic histidine 160. We show that the A. actinomycetemcomitans DO15 isolate secretes CdtBΔ116–188, and that this subunit cannot form a holotoxin and is also not genotoxic if expressed ectopically in HeLa cells. Furthermore, the A. actinomycetemcomitans DO15 isolate is not toxic, nor does it induce cellular distention upon infection of co-cultivated HeLa cells. Biological significance of this deletion in the cdtB remains to be explained.
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Affiliation(s)
- Davor Obradović
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Rok Gašperšič
- Department of Oral Medicine and Periodontology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Simon Caserman
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Adrijana Leonardi
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Maja Jamnik
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Zdravko Podlesek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Katja Seme
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Peter Maček
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- * E-mail: (PM); (MB)
| | - Matej Butala
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- * E-mail: (PM); (MB)
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Yoshimoto T, Fujita T, Kajiya M, Ouhara K, Matsuda S, Komatsuzawa H, Shiba H, Kurihara H. Aggregatibacter actinomycetemcomitans outer membrane protein 29 (Omp29) induces TGF-β-regulated apoptosis signal in human gingival epithelial cells via fibronectin/integrinβ1/FAK cascade. Cell Microbiol 2016; 18:1723-1738. [PMID: 27121139 DOI: 10.1111/cmi.12607] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/21/2016] [Accepted: 04/21/2016] [Indexed: 12/25/2022]
Abstract
Gingival junctional epithelial cell apoptosis caused by periodontopathic bacteria exacerbates periodontitis. This pathological apoptosis is involved in the activation of transforming growth factor β (TGF-β). However, the molecular mechanisms by which microbes induce the activation of TGF-β remain unclear. We previously reported that Aggregatibacter actinomycetemcomitans (Aa) activated TGF-β receptor (TGF-βR)/smad2 signalling to induce epithelial cell apoptosis, even though Aa cannot bind to TGF-βR. Additionally, outer membrane protein 29 kDa (Omp29), a member of the Aa Omps family, can induce actin rearrangements via focal adhesion kinase (FAK) signalling, which also plays a role in the activation of TGF-β by cooperating with integrin. Accordingly, we hypothesized that Omp29-induced actin rearrangements via FAK activity would enhance the activation of TGF-β, leading to gingival epithelial cell apoptosis in vitro. By using human gingival epithelial cell line OBA9, we found that Omp29 activated TGF-βR/smad2 signalling and decreased active TGF-β protein levels in the extracellular matrix (ECM) of cell culture, suggesting the transactivation of TGF-βR. Inhibition of actin rearrangements by cytochalasin D or blebbistatin and knockdown of FAK or integrinβ1 expression by siRNA transfection attenuated TGF-βR/smad2 signalling activity and reduction of TGF-β levels in the ECM caused by Omp29. Furthermore, Omp29 bound to fibronectin (Fn) to induce its aggregation on integrinβ1, which is associated with TGF-β signalling activity. All the chemical inhibitors and siRNAs tested blocked Omp29-induced OBA9 cells apoptosis. These results suggest that Omp29 binds to Fn in order to facilitate Fn/integrinβ1/FAK signalling-dependent TGF-β release from the ECM, thereby inducing gingival epithelial cell apoptosis via TGF-βR/smad2 pathway.
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Affiliation(s)
- Tetsuya Yoshimoto
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tsuyoshi Fujita
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Mikihito Kajiya
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kazuhisa Ouhara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Shinji Matsuda
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hitoshi Komatsuzawa
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hideki Shiba
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hidemi Kurihara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
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16
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Kawamoto D, Ando-Suguimoto ES, Bueno-Silva B, DiRienzo JM, Mayer MPA. Alteration of Homeostasis in Pre-osteoclasts Induced by Aggregatibacter actinomycetemcomitans CDT. Front Cell Infect Microbiol 2016; 6:33. [PMID: 27064424 PMCID: PMC4815040 DOI: 10.3389/fcimb.2016.00033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/07/2016] [Indexed: 01/28/2023] Open
Abstract
The dysbiotic microbiota associated with aggressive periodontitis includes Aggregatibacter actinomycetemcomitans, the only oral species known to produce a cytolethal distending toxin (AaCDT). Give that CDT alters the cytokine profile in monocytic cells, we aimed to test the hypothesis that CDT plays a role in bone homeostasis by affecting the differentiation of precursor cells into osteoclasts. Recombinant AaCDT was added to murine bone marrow monocytes (BMMC) in the presence or absence of RANKL and the cell viability and cytokine profile of osteoclast precursor cells were determined. Multinucleated TRAP(+) cell numbers, and relative transcription of genes related to osteoclastogenesis were also evaluated. The addition of AaCDT did not lead to loss in cell viability but promoted an increase in the average number of TRAP(+) cells with 1-2 nuclei in the absence or presence of RANKL (Tukey, p < 0.05). This increase was also observed for TRAP(+) cells with ≥3nuclei, although this difference was not significant. Levels of TGF-β, TNF-α, and IL-6, in the supernatant fraction of cells, were higher when in AaCDT exposed cells, whereas levels of IL-1β and IL-10 were lower than controls under the same conditions. After interaction with AaCDT, transcription of the rank (encoding the receptor RANK), nfatc1 (transcription factor), and ctpK (encoding cathepsin K) genes was downregulated in pre-osteoclastic cells. The data indicated that despite the presence of RANKL and M-CSF, AaCDT may inhibit osteoclast differentiation by altering cytokine profiles and repressing transcription of genes involved in osteoclastogenesis. Therefore, the CDT may impair host defense mechanisms in periodontitis.
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Affiliation(s)
- Dione Kawamoto
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Ellen S Ando-Suguimoto
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Bruno Bueno-Silva
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Joseph M DiRienzo
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania PA, USA
| | - Marcia P A Mayer
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
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17
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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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18
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Characterization of A. actinomycetemcomitans strains in subgingival samples from periodontitis subjects in Morocco. Clin Oral Investig 2015; 20:1809-18. [DOI: 10.1007/s00784-015-1653-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
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19
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Doğan B, Chen J, Çiftlikli SY, Huang J, Kadir T, Alnıak AK, Chen C. Occurrence and serotype distribution of Aggregatibacter actinomycetemcomitans in subjects without periodontitis in Turkey. Arch Oral Biol 2015; 61:125-9. [PMID: 26556547 DOI: 10.1016/j.archoralbio.2015.10.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 09/25/2015] [Accepted: 10/25/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the occurrence and serotype distribution of Aggregatibacter actinomycetemcomitans in subjects without periodontitis. DESIGN Systemically healthy dental students without periodontitis (n=94), who had not used antibiotics within the last 3 months or received any form of periodontal therapy within the last 6 months, were included in the study. Pooled subgingival microbiological samples were collected from 4 first molars and 4 central incisors in each subject using sterile paper points. All samples were tested for the presence and the serotype of A. actinomycetemcomitans through PCR analysis of the 16S rRNA genes and the serotype-specific gene clusters in the DNA extracted from the samples. RESULTS Of the 94 samples that were tested, 43 (46%) were positive for A. actinomycetemcomitans. No statistically significant differences in clinical parameters were found between subgingival sites with or without detectable A. actinomycetemcomitans (t-test, P>0.01). Among the 43 A. actinomycetemcomitans-positive samples, the serotype was identified in 21 samples. Fifteen were positive for A. actinomycetemcomitans serotype a, 1 for serotype b, 1 for serotype c, and 4 for serotype f, while serotypes d and e were not detected. CONCLUSION A. actinomycetemcomitans serotype a is the most commonly found serotype among Turkish dental students without periodontitis.
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Affiliation(s)
- Başak Doğan
- Department of Periodontology, Faculty of Dentistry, Marmara University, Istanbul, Turkey
| | - Jason Chen
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Ostrow School of Dentistry, University of Southern California, USA
| | - Sinem Yıldız Çiftlikli
- Department of Periodontology, Faculty of Dentistry, Marmara University, Istanbul, Turkey
| | - Jonathan Huang
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Ostrow School of Dentistry, University of Southern California, USA
| | - Tanju Kadir
- Department of Microbiology, Faculty of Dentistry, Marmara University, Istanbul, Turkey
| | - Anıl Kınacı Alnıak
- Department of Periodontology, Faculty of Dentistry, Marmara University, Istanbul, Turkey
| | - Casey Chen
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Ostrow School of Dentistry, University of Southern California, USA.
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20
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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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21
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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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22
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Lopez R, Hujoel P, Belibasakis GN. On putative periodontal pathogens: an epidemiological perspective. Virulence 2015; 6:249-57. [PMID: 25874553 PMCID: PMC4601192 DOI: 10.1080/21505594.2015.1014266] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 12/19/2022] Open
Abstract
The current understanding on the role of microbiology on periodontitis causation is reviewed. An appraisal of the literature reveals several issues that have limited the attempts to investigate candidate periodontal pathogens as causes of periodontitis and confirms that only limited epidemiological evidence is available. Several aspects of the contemporary understanding on causal inference are discussed with examples for periodontitis.
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Affiliation(s)
- Rodrigo Lopez
- Section of Periodontology; Faculty of Health Sciences; Aarhus University; Aarhus, Denmark
| | - Philippe Hujoel
- Department of Oral Health Sciences; School of Dentistry and Department of Epidemiology; School of Public Health; University of Washington; Seattle, WA, USA
| | - Georgios N Belibasakis
- Section of Oral Microbiology and Immunology; Institute of Oral Biology; Center of Dental Medicine; University of Zürich; Zürich, Switzerland
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Abstract
Some of the most potent toxins produced by plants and bacteria are members of a large family known as the AB toxins. AB toxins are generally characterized by a heterogenous complex consisting of two protein chains arranged in various monomeric or polymeric configurations. The newest class within this superfamily is the cytolethal distending toxin (Cdt). The Cdt is represented by a subfamily of toxins produced by a group of taxonomically distinct Gram negative bacteria. Members of this subfamily have a related AB-type chain or subunit configuration and properties distinctive to the AB paradigm. In this review, the unique structural and cytotoxic properties of the Cdt subfamily, target cell specificities, intoxication pathway, modes of action, and relationship to the AB toxin superfamily are compared and contrasted.
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24
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Yoshimoto T, Fujita T, Ouhara K, Kajiya M, Imai H, Shiba H, Kurihara H. Smad2 is involved in Aggregatibacter actinomycetemcomitans-induced apoptosis. J Dent Res 2014; 93:1148-54. [PMID: 25192897 DOI: 10.1177/0022034514550041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Apoptosis is thought to contribute to the progression of periodontitis. It has been suggested that the apoptosis of epithelial cells may contribute to the loss of epithelial barrier function. Smad2, a downstream signaling molecule of TGF-β receptors (TGF-βRs), is critically involved in apoptosis in several cell types. However, the relationship between smad2 and bacteria-induced apoptosis has not yet been elucidated. It is possible that the regulation of apoptosis induced by periodontopathic bacteria may lead to novel preventive therapies for periodontitis. Therefore, in the present study, we investigated the involvement of smad2 phosphorylation in apoptosis of human gingival epithelial cells induced by Aggregatibacter actinomycetemcomitans (Aa). Aa apparently induced the phosphorylation of smad2 in primary human gingival epithelial cells (HGECs) or the human gingival epithelial cell line, OBA9 cells. In addition, Aa induced phosphorylation of the serine residue of the TGF-β type I receptor (TGF-βRI) in OBA9 cells. SB431542 (a TGF-βRI inhibitor) and siRNA transfection for TGF-βRI, which reduced both TGF-βRI mRNA and protein levels, markedly attenuated the Aa-induced phosphorylation of smad2. Furthermore, the disruption of TGF-βRI signaling cascade by SB431542 and siRNA transfection for TGF-βRI abrogated the activation of cleaved caspase-3 expression and repressed apoptosis in OBA9 cells treated with Aa. Thus, Aa induced apoptosis in gingival epithelial cells by activating the TGF-βRI-smad2-caspase-3 signaling pathway. The results of the present study may suggest that the periodontopathic bacteria, Aa, activates the TGF-βR/smad2 signaling pathway in human gingival epithelial cells and induces apoptosis in epithelial cells, which may lead to new therapeutic strategies that modulate the initiation of periodontitis.
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Affiliation(s)
- T Yoshimoto
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - T Fujita
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - K Ouhara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - M Kajiya
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Imai
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Shiba
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Kurihara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
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Saraiva L, Rebeis ES, Martins EDS, Sekiguchi RT, Ando-Suguimoto ES, Mafra CES, Holzhausen M, Romito GA, Mayer MPA. IgG sera levels against a subset of periodontopathogens and severity of disease in aggressive periodontitis patients: a cross-sectional study of selected pocket sites. J Clin Periodontol 2014; 41:943-51. [DOI: 10.1111/jcpe.12296] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2014] [Indexed: 12/17/2022]
Affiliation(s)
- Luciana Saraiva
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Estela S. Rebeis
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Eder de S. Martins
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Ricardo T. Sekiguchi
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Ellen S. Ando-Suguimoto
- Department of Microbiology; Institute of Biomedical Sciences; University of São Paulo; São Paulo SP Brazil
| | | | - Marinella Holzhausen
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Giuseppe A. Romito
- Department of Periodontology; Dental School; University of São Paulo; São Paulo SP Brazil
| | - Marcia P. A. Mayer
- Department of Microbiology; Institute of Biomedical Sciences; University of São Paulo; São Paulo SP Brazil
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26
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Haubek D, Johansson A. Pathogenicity of the highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans and its geographic dissemination and role in aggressive periodontitis. J Oral Microbiol 2014; 6:23980. [PMID: 25206940 PMCID: PMC4139931 DOI: 10.3402/jom.v6.23980] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 02/01/2023] Open
Abstract
For decades, Aggregatibacter actinomycetemcomitans has been associated with aggressive forms of periodontitis in adolescents. In the middle of the 1990s, a specific JP2 clone of A. actinomycetemcomitans, belonging to the cluster of serotype b strains of A. actinomycetemcomitans and having a number of other characteristics, was found to be strongly associated with aggressive forms of periodontitis, particularly in North Africa. Although several longitudinal studies still point to the bacterial species, A. actinomycetemcomitans as a risk factor of aggressive periodontitis, it is now also widely accepted that the highly leukotoxic JP2 clone of A. actinomycetemcomitans is implicated in rapidly progressing forms of aggressive periodontitis. The JP2 clone strains are highly prevalent in human populations living in Northern and Western parts of Africa. These strains are also prevalent in geographically widespread populations that have originated from the Northwest Africa. Only sporadic signs of a dissemination of the JP2 clone strains to non-African populations have been found despite Africans living geographically widespread for hundreds of years. It remains an unanswered question if a particular host tropism exists as a possible explanation for the frequent colonization of the Northwest African population with the JP2 clone. Two exotoxins of A. actinomycetemcomitans are known, leukotoxin (LtxA) and cytolethal distending toxin (Cdt). LtxA is able to kill human immune cells, and Cdt can block cell cycle progression in eukaryotic cells and thus induce cell cycle arrest. Whereas the leukotoxin production is enhanced in JP2 clone strains thus increasing the virulence potential of A. actinomycetemcomitans, it has not been possible so far to demonstrate such a role for Cdt. Lines of evidence have led to the understanding of the highly leukotoxic JP2 clone of A. actinomycetemcomitans as an aetiological factor of aggressive periodontitis. Patients, who are colonized with the JP2 clone, are likely to share this clone with several family members because the clone is transmitted through close contacts. This is a challenge to the clinicians. The patients need intense monitoring of their periodontal status as the risk for developing severely progressing periodontal lesions are relatively high. Furthermore, timely periodontal treatment, in some cases including periodontal surgery supplemented by the use of antibiotics, is warranted. Preferably, periodontal attachment loss should be prevented by early detection of the JP2 clone of A. actinomycetemcomitans by microbial diagnostic testing and/or by preventive means.
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Affiliation(s)
- Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus, Denmark
| | - Anders Johansson
- Department of Molecular Periodontology, Umea University, Umea, Sweden
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Höglund Åberg C, Haubek D, Kwamin F, Johansson A, Claesson R. Leukotoxic activity of Aggregatibacter actinomycetemcomitans and periodontal attachment loss. PLoS One 2014; 9:e104095. [PMID: 25093857 PMCID: PMC4122431 DOI: 10.1371/journal.pone.0104095] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 07/08/2014] [Indexed: 11/19/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative periodontitis-associated bacterium that expresses a toxin that selectively affects leukocytes. This leukotoxin is encoded by an operon belonging to the core genome of this bacterial species. Variations in the expression of the leukotoxin have been reported, and a well-characterized specific clonal type (JP2) of this bacterium with enhanced leukotoxin expression has been isolated. In particular, the presence of the JP2 genotype significantly increases the risk for the progression of periodontal attachment loss (AL). Based on these findings we hypothesized that variations in the leukotoxicity are linked to disease progression in infected individuals. In the present study, the leukotoxicity of 239 clinical isolates of A. actinomycetemcomitans was analysed with different bioassays, and the genetic peculiarities of the isolates were related to their leukotoxicity based on examination with molecular techniques. The periodontal status of the individuals sampled for the presence of A. actinomycetemcomitans was examined longitudinally, and the importance of the observed variations in leukotoxicity was evaluated in relation to disease progression. Our data show that high leukotoxicity correlates with an enhanced risk for the progression of AL. The JP2 genotype isolates were all highly leukotoxic, while the isolates with an intact leukotoxin promoter (non-JP2 genotypes) showed substantial variation in leukotoxicity. Genetic characterization of the non-JP2 genotype isolates indicated the presence of highly leukotoxic genotypes of serotype b with similarities to the JP2 genotype. Based on these results, we conclude that A. actinomycetemcomitans harbours other highly virulent genotypes besides the previously described JP2 genotype. In addition, the results from the present study further highlight the importance of the leukotoxin as a key virulence factor in aggressive forms of periodontitis.
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Affiliation(s)
- Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Faculty of Medicine, 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, Faculty of Medicine, Umeå University, Umeå, Sweden
| | - Rolf Claesson
- Oral Microbiology, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden
- * E-mail:
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Breaking the Gingival Epithelial Barrier: Role of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin in Oral Infectious Disease. Cells 2014; 3:476-99. [PMID: 24861975 PMCID: PMC4092858 DOI: 10.3390/cells3020476] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/08/2014] [Accepted: 05/15/2014] [Indexed: 12/17/2022] Open
Abstract
The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is part of the HACEK group that causes infective endocarditis, a constituent of the oral flora that promotes some forms of periodontal disease and a member of the family of species that secrete a cytolethal distending toxin (Cdt). The family of bacteria that express the cdt genes participate in diseases that involve the disruption of a mucosal or epithelial layer. In vitro studies have shown that human gingival epithelial cells (HGEC) are native targets of the Cdt that typically induces DNA damage that signals growth arrest at the G2/M interphase of the cell cycle. The gingival epithelium is an early line of defense in the oral cavity against microbial assault. When damaged, bacteria collectively gain entry into the underlying connective tissue where microbial products can affect processes and pathways in infiltrating inflammatory cells culminating in the destruction of the attachment apparatus of the tooth. One approach has been the use of an ex vivo gingival explant model to assess the effects of the Cdt on the morphology and integrity of the tissue. The goal of this review is to provide an overview of these studies and to critically examine the potential contribution of the Cdt to the breakdown of the protective gingival barrier.
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