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Kim TJ, Shenker BJ, MacElroy AS, Spradlin S, Walker LP, Boesze-Battaglia K. Aggregatibacter actinomycetemcomitans cytolethal distending toxin modulates host phagocytic function. Front Cell Infect Microbiol 2023; 13:1220089. [PMID: 37719670 PMCID: PMC10500838 DOI: 10.3389/fcimb.2023.1220089] [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: 05/10/2023] [Accepted: 08/10/2023] [Indexed: 09/19/2023] Open
Abstract
Cytolethal distending toxins (Cdt) are a family of toxins produced by several human pathogens which infect mucocutaneous tissue and induce inflammatory disease. Human macrophages exposed to Aggregatibacter actinomycetemcomitans (Aa) Cdt respond through canonical and non-canonical inflammasome activation to stimulate cytokine release. The inflammatory response is dependent on PI3K signaling blockade via the toxin's phosphatidylinositol-3,4,5-triphosphate (PIP3) phosphatase activity; converting PIP3 to phosphatidylinsoitol-3,4-diphosphate (PI3,4P2) thereby depleting PIP3 pools. Phosphoinositides, also play a critical role in phagosome trafficking, serving as binding domains for effector proteins during phagosome maturation and subsequent fusion with lysosomes. We now demonstrate that AaCdt manipulates the phosphoinositide (PI) pools of phagosome membranes and alters Rab5 association. Exposure of macrophages to AaCdt slowed phagosome maturation and decreased phago-lysosome formation, thereby compromising macrophage phagocytic function. Moreover, macrophages exposed to Cdt showed decreased bactericidal capacity leading to increase in Aggregatibacter actinomycetemcomitans survival. Thus, Cdt may contribute to increased susceptibility to bacterial infection. These studies uncover an underexplored aspect of Cdt function and provide new insight into the virulence potential of Cdt in mediating the pathogenesis of disease caused by Cdt-producing organisms such as Aa.
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Affiliation(s)
- Taewan J. Kim
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Bruce J. Shenker
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Andrew S. MacElroy
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Samuel Spradlin
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Lisa P. Walker
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Virulence Factors of the Periodontal Pathogens: Tools to Evade the Host Immune Response and Promote Carcinogenesis. Microorganisms 2023; 11:microorganisms11010115. [PMID: 36677408 PMCID: PMC9860638 DOI: 10.3390/microorganisms11010115] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
Periodontitis is the most common chronic, inflammatory oral disease that affects more than half of the population in the United States. The disease leads to destruction of the tooth-supporting tissue called periodontium, which ultimately results in tooth loss if uncured. The interaction between the periodontal microbiota and the host immune cells result in the induction of a non-protective host immune response that triggers host tissue destruction. Certain pathogens have been implicated periodontal disease formation that is triggered by a plethora of virulence factors. There is a collective evidence on the impact of periodontal disease progression on systemic health. Of particular interest, the role of the virulence factors of the periodontal pathogens in facilitating the evasion of the host immune cells and promotion of carcinogenesis has been the focus of many researchers. The aim of this review is to examine the influence of the periodontal pathogens Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), and Fusobacterium nucleatum (F. nucleatum) in the modulation of the intracellular signaling pathways of the host cells in order to evade the host immune response and interfere with normal host cell death and the role of their virulence factors in this regard.
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Hakmi M, Bouricha EM, El Harti J, Amzazi S, Belyamani L, Khanfri JE, Ibrahimi A. Computational modeling and druggability assessment of Aggregatibacter actinomycetemcomitans leukotoxin. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 222:106952. [PMID: 35724475 DOI: 10.1016/j.cmpb.2022.106952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/30/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
The leukotoxin (LtxA) of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is a protein exotoxin belonging to the repeat-in-toxin family (RTX). Numerous studies have demonstrated that LtxA may play a critical role in the pathogenicity of A. actinomycetemcomitans since hyper-leukotoxic strains have been associated with severe disease. Accordingly, considerable effort has been made to elucidate the mechanisms by which LtxA interacts with host cells and induce their death. However, these attempts have been hampered by the unavailability of a tertiary structure of the toxin, which limits the understanding of its molecular properties and mechanisms. In this paper, we used homology and template free modeling algorithms to build the complete tertiary model of LtxA at atomic level in its calcium-bound Holo-state. The resulting model was refined by energy minimization, validated by Molprobity and ProSA tools, and subsequently subjected to a cumulative 600ns of all-atom classical molecular dynamics simulation to evaluate its structural aspects. The druggability of the proposed model was assessed using Fpocket and FTMap tools, resulting in the identification of four putative cavities and fifteen binding hotspots that could be targeted by rational drug design tools to find new ligands to inhibit LtxA activity.
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Affiliation(s)
- Mohammed Hakmi
- Medical Biotechnology Laboratory (MedBiotech), Bioinova Research Center, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Morocco
| | - El Mehdi Bouricha
- Medical Biotechnology Laboratory (MedBiotech), Bioinova Research Center, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Morocco
| | - Jaouad El Harti
- Therapeutic Chemistry Laboratory, Medical Biotechnology Laboratory (MedBiotech), Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Morocco
| | - Said Amzazi
- Laboratory of Human Pathologies Biology, Department of Biology, Faculty of Sciences, and Genomic Center of Human Pathologies, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Lahcen Belyamani
- Emergency Department, Military Hospital Mohammed V, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Jamal Eddine Khanfri
- Medical Biotechnology Laboratory (MedBiotech), Bioinova Research Center, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Morocco
| | - Azeddine Ibrahimi
- Medical Biotechnology Laboratory (MedBiotech), Bioinova Research Center, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Morocco.
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Portes J, Bullón B, Quiles JL, Battino M, Bullón P. Diabetes Mellitus and Periodontitis Share Intracellular Disorders as the Main Meeting Point. Cells 2021; 10:cells10092411. [PMID: 34572060 PMCID: PMC8467361 DOI: 10.3390/cells10092411] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/09/2021] [Accepted: 09/11/2021] [Indexed: 12/15/2022] Open
Abstract
Diabetes and periodontitis are two of the most prevalent diseases worldwide that negatively impact the quality of life of the individual suffering from them. They are part of the chronic inflammatory disease group or, as recently mentioned, non-communicable diseases, with inflammation being the meeting point among them. Inflammation hitherto includes vascular and tissue changes, but new technologies provide data at the intracellular level that could explain how the cells respond to the aggression more clearly. This review aims to emphasize the molecular pathophysiological mechanisms in patients with type 2 diabetes mellitus and periodontitis, which are marked by different impaired central regulators including mitochondrial dysfunction, impaired immune system and autophagy pathways, oxidative stress, and the crosstalk between adenosine monophosphate-activated protein kinase (AMPK) and the renin-angiotensin system (RAS). All of them are the shared background behind both diseases that could explain its relationship. These should be taken in consideration if we would like to improve the treatment outcomes. Currently, the main treatment strategies in diabetes try to reduce glycemia index as the most important aspect, and in periodontitis try to reduce the presence of oral bacteria. We propose to add to the therapeutic guidelines the handling of all the intracellular disorders to try to obtain better treatment success.
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Affiliation(s)
- Juliana Portes
- Department of Periodontology, Dental School, University of Seville, C/Avicena, s/n, 41009 Seville, Spain; (J.P.); (B.B.)
| | - Beatriz Bullón
- Department of Periodontology, Dental School, University of Seville, C/Avicena, s/n, 41009 Seville, Spain; (J.P.); (B.B.)
| | - José Luis Quiles
- Biomedical Research Center (CIBM), Department of Physiology, University Campus of Cartuja, Institute of Nutrition and Food Technology “José Mataix Verdú”, University of Granada, 18071 Granada, Spain;
- Research Group on Foods, Nutritional Biochemistry and Health, Universidad Europea del Atlántico, C/Isabel Torres, 21, 39011 Santander, Spain
| | - Maurizio Battino
- Department of Clinical Sciences, Faculty of Medicine, Università Politecnica delle Marche. Via Tronto 10A, 60126 Torrette di Ancona, Italy;
- International Research Center for Food Nutrition and Safety, Jiangsu University, 301 Xuefu Rd, Zhenjiang 212013, China
| | - Pedro Bullón
- Department of Periodontology, Dental School, University of Seville, C/Avicena, s/n, 41009 Seville, Spain; (J.P.); (B.B.)
- Correspondence:
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Oscarsson J, DiRienzo J, Johansson A. Editorial Comments to the Special Issue: " Aggregatibacter actinomycetemcomitans-Gram-Negative Bacterial Pathogen". Pathogens 2020; 9:E441. [PMID: 32512822 PMCID: PMC7350384 DOI: 10.3390/pathogens9060441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a periodontal pathogen colonizing the oral cavity in many individuals of the human population. It is equipped with several potent virulence factors that can cause cell death and induce or evade the host inflammatory response. Both harmless and highly virulent genotypes of the bacterium have emerged because of the large genetic diversity within the species. 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 editorial, the different genetic and virulence properties of A. actinomycetemcomitans will be addressed in relation to the publications in this Special Issue.
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Affiliation(s)
- Jan Oscarsson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden;
| | - Joseph DiRienzo
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104-6030, USA;
| | - Anders Johansson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden;
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