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Zhu J, Li M, Li J, Wu J. Sialic acid metabolism of oral bacteria and its potential role in colorectal cancer and Alzheimer's disease. Carbohydr Res 2024; 541:109172. [PMID: 38823062 DOI: 10.1016/j.carres.2024.109172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/10/2024] [Accepted: 05/29/2024] [Indexed: 06/03/2024]
Abstract
Sialic acid metabolism in oral bacteria is a complex process involving nutrient acquisition, immune evasion, cell surface modification, and the production of metabolites that contribute to bacterial persistence and virulence in the oral cavity. In addition to causing various periodontal diseases, certain oral pathogenic bacteria, such as Porphyromonas gingivalis, Tannerella forsythia, and Fusobacterium nucleatum, can induce inflammatory reactions and influence the immunity of host cells. These associations with host cells are linked to various diseases, particularly colorectal cancer and Alzheimer's disease. Sialic acid can be found in the host oral mucosa, saliva, or food residues in the oral cavity, and it may promote the colonization of oral bacteria and contribute to disease development. This review aims to summarize the role of sialic acid metabolism in oral bacteria and discuss its effect on the pathogenesis of colorectal cancer and Alzheimer's disease.
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Affiliation(s)
- Jiao Zhu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Mengyang Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Jinfang Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Jianrong Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
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2
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Pham C, Guo S, Han X, Coleman L, Sze CW, Wang H, Liu J, Li C. A pleiotropic role of sialidase in the pathogenicity of Porphyromonas gingivalis. Infect Immun 2024; 92:e0034423. [PMID: 38376159 PMCID: PMC10929438 DOI: 10.1128/iai.00344-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/01/2024] [Indexed: 02/21/2024] Open
Abstract
As one of the keystone pathogens of periodontitis, the oral bacterium Porphyromonas gingivalis produces an array of virulence factors, including a recently identified sialidase (PG0352). Our previous report involving loss-of-function studies indicated that PG0352 plays an important role in the pathophysiology of P. gingivalis. However, this report had not been corroborated by gain-of-function studies or substantiated in different P. gingivalis strains. To fill these gaps, herein we first confirm the role of PG0352 in cell surface structures (e.g., capsule) and serum resistance using P. gingivalis W83 strain through genetic complementation and then recapitulate these studies using P. gingivalis ATCC33277 strain. We further investigate the role of PG0352 and its counterpart (PGN1608) in ATCC33277 in cell growth, biofilm formation, neutrophil killing, cell invasion, and P. gingivalis-induced inflammation. Our results indicate that PG0352 and PGN1608 are implicated in P. gingivalis cell surface structures, hydrophobicity, biofilm formation, resistance to complement and neutrophil killing, and host immune responses. Possible molecular mechanisms involved are also discussed. In summary, this report underscores the importance of sialidases in the pathophysiology of P. gingivalis and opens an avenue to elucidate their underlying molecular mechanisms.
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Affiliation(s)
- Christopher Pham
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shuaiqi Guo
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Xiao Han
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Laurynn Coleman
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ching Wooen Sze
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Huizhi Wang
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Chunhao Li
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, USA
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3
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Johnston CD, Goetting-Minesky MP, Kennedy K, Godovikova V, Zayed SM, Roberts RS, Fenno JC. Enhanced transformation efficiency in Treponema denticola enabled by SyngenicDNA-based plasmids lacking restriction-modification target motifs. Mol Oral Microbiol 2023; 38:455-470. [PMID: 37880921 PMCID: PMC11024988 DOI: 10.1111/omi.12441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/25/2023] [Accepted: 10/08/2023] [Indexed: 10/27/2023]
Abstract
Oral spirochetes are among a small group of keystone pathogens contributing to dysregulation of tissue homeostatic processes that leads to breakdown of the tissue and bone supporting the teeth in periodontal disease. Additionally, our group has recently demonstrated that Treponema are among the dominant microbial genera detected intracellularly in tumor specimens from patients with oral squamous cell carcinoma. While over 60 species and phylotypes of oral Treponema have been detected, T. denticola is one of the few that can be grown in culture and the only one in which genetic manipulation is regularly performed. Thus, T. denticola is a key model organism for studying spirochete metabolic processes, interactions with other microbes, and host cell and tissue responses relevant to oral diseases, as well as venereal and nonvenereal treponematoses whose agents lack workable genetic systems. We previously demonstrated improved transformation efficiency using an Escherichia coli-T. denticola shuttle plasmid and its utility for expression in T. denticola of an exogenous fluorescent protein that is active under anaerobic conditions. Here, we expand on this work by characterizing T. denticola Type I and Type II restriction-modification (R-M) systems and designing a high-efficiency R-M-silent "SyngenicDNA" shuttle plasmid resistant to all T. denticola ATCC 35405 R-M systems. Resequencing of the ATCC 33520 genome revealed an additional Type I R-M system consistent with the relatively low transformation efficiency of the shuttle plasmid in this strain. Using SyngenicDNA approaches, we optimized shuttle plasmid transformation efficiency in T. denticola and used it to complement a defined T. denticola ΔfhbB mutant strain. We further report the first high-efficiency transposon mutagenesis of T. denticola using an R-M-silent, codon-optimized, himarC9 transposase-based plasmid. Thus, use of SyngenicDNA-based strategies and tools can enable further mechanistic examinations of T. denticola physiology and behavior.
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Affiliation(s)
- Christopher D. Johnston
- Vaccine and Infection Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - M. Paula Goetting-Minesky
- Department of Biologic and Materials Sciences and Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109
| | - Kelly Kennedy
- Vaccine and Infection Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Valentina Godovikova
- Department of Biologic and Materials Sciences and Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109
| | - Sara M. Zayed
- Department of Biologic and Materials Sciences and Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109
| | | | - J. Christopher Fenno
- Department of Biologic and Materials Sciences and Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109
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Clark ND, Pham C, Kurniyati K, Sze CW, Coleman L, Fu Q, Zhang S, Malkowski MG, Li C. Functional and structural analyses reveal that a dual domain sialidase protects bacteria from complement killing through desialylation of complement factors. PLoS Pathog 2023; 19:e1011674. [PMID: 37747935 PMCID: PMC10553830 DOI: 10.1371/journal.ppat.1011674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/05/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023] Open
Abstract
The complement system is the first line of innate immune defense against microbial infections. To survive in humans and cause infections, bacterial pathogens have developed sophisticated mechanisms to subvert the complement-mediated bactericidal activity. There are reports that sialidases, also known as neuraminidases, are implicated in bacterial complement resistance; however, its underlying molecular mechanism remains elusive. Several complement proteins (e.g., C1q, C4, and C5) and regulators (e.g., factor H and C4bp) are modified by various sialoglycans (glycans with terminal sialic acids), which are essential for their functions. This report provides both functional and structural evidence that bacterial sialidases can disarm the complement system via desialylating key complement proteins and regulators. The oral bacterium Porphyromonas gingivalis, a "keystone" pathogen of periodontitis, produces a dual domain sialidase (PG0352). Biochemical analyses reveal that PG0352 can desialylate human serum and complement factors and thus protect bacteria from serum killing. Structural analyses show that PG0352 contains a N-terminal carbohydrate-binding module (CBM) and a C-terminal sialidase domain that exhibits a canonical six-bladed β-propeller sialidase fold with each blade composed of 3-4 antiparallel β-strands. Follow-up functional studies show that PG0352 forms monomers and is active in a broad range of pH. While PG0352 can remove both N-acetylneuraminic acid (Neu5Ac) and N-glycolyl-neuraminic acid (Neu5Gc), it has a higher affinity to Neu5Ac, the most abundant sialic acid in humans. Structural and functional analyses further demonstrate that the CBM binds to carbohydrates and serum glycoproteins. The results shown in this report provide new insights into understanding the role of sialidases in bacterial virulence and open a new avenue to investigate the molecular mechanisms of bacterial complement resistance.
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Affiliation(s)
- Nicholas D. Clark
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York, United States of America
| | - Christopher Pham
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kurni Kurniyati
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ching Wooen Sze
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Laurynn Coleman
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Qin Fu
- Proteomics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America
| | - Sheng Zhang
- Proteomics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America
| | - Michael G. Malkowski
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York, United States of America
| | - Chunhao Li
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
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5
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Muñoz-Provencio D, Yebra MJ. Gut Microbial Sialidases and Their Role in the Metabolism of Human Milk Sialylated Glycans. Int J Mol Sci 2023; 24:9994. [PMID: 37373145 DOI: 10.3390/ijms24129994] [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: 04/21/2023] [Revised: 05/26/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Sialic acids (SAs) are α-keto-acid sugars with a nine-carbon backbone present at the non-reducing end of human milk oligosaccharides and the glycan moiety of glycoconjugates. SAs displayed on cell surfaces participate in the regulation of many physiologically important cellular and molecular processes, including signaling and adhesion. Additionally, sialyl-oligosaccharides from human milk act as prebiotics in the colon by promoting the settling and proliferation of specific bacteria with SA metabolism capabilities. Sialidases are glycosyl hydrolases that release α-2,3-, α-2,6- and α-2,8-glycosidic linkages of terminal SA residues from oligosaccharides, glycoproteins and glycolipids. The research on sialidases has been traditionally focused on pathogenic microorganisms, where these enzymes are considered virulence factors. There is now a growing interest in sialidases from commensal and probiotic bacteria and their potential transglycosylation activity for the production of functional mimics of human milk oligosaccharides to complement infant formulas. This review provides an overview of exo-alpha-sialidases of bacteria present in the human gastrointestinal tract and some insights into their biological role and biotechnological applications.
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Affiliation(s)
- Diego Muñoz-Provencio
- Department of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Av. Agustín Escardino 7, 46980 Paterna, Spain
| | - María J Yebra
- Department of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Av. Agustín Escardino 7, 46980 Paterna, Spain
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6
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Pisani F, Pisani V, Arcangeli F, Harding A, Singhrao SK. Treponema denticola Has the Potential to Cause Neurodegeneration in the Midbrain via the Periodontal Route of Infection-Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6049. [PMID: 37297653 PMCID: PMC10252855 DOI: 10.3390/ijerph20116049] [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: 02/26/2023] [Revised: 03/30/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease and the most common example of dementia. The neuropathological features of AD are the abnormal deposition of extracellular amyloid-β (Aβ) and intraneuronal neurofibrillary tangles with hyperphosphorylated tau protein. It is recognized that AD starts in the frontal cerebral cortex, and then it progresses to the entorhinal cortex, the hippocampus, and the rest of the brain. However, some studies on animals suggest that AD could also progress in the reverse order starting from the midbrain and then spreading to the frontal cortex. Spirochetes are neurotrophic: From a peripheral route of infection, they can reach the brain via the midbrain. Their direct and indirect effect via the interaction of their virulence factors and the microglia potentially leads to the host peripheral nerve, the midbrain (especially the locus coeruleus), and cortical damage. On this basis, this review aims to discuss the hypothesis of the ability of Treponema denticola to damage the peripheral axons in the periodontal ligament, to evade the complemental pathway and microglial immune response, to determine the cytoskeletal impairment and therefore causing the axonal transport disruption, an altered mitochondrial migration and the consequent neuronal apoptosis. Further insights about the central neurodegeneration mechanism and Treponema denticola's resistance to the immune response when aggregated in biofilm and its quorum sensing are suggested as a pathogenetic model for the advanced stages of AD.
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Affiliation(s)
- Flavio Pisani
- Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
| | - Valerio Pisani
- IRCCS, “Santa Lucia” Foundation, Neurology and Neurorehabilitation Unit, Via Ardeatina, 306, 00179 Rome, Italy
| | - Francesca Arcangeli
- Azienda Sanitaria Locale ASLRM1, Nuovo Regina Margherita Hospital, Geriatric Department, Advanced Centre for Dementia and Cognitive Disorders, Via Emilio Morosini, 30, 00153 Rome, Italy
| | - Alice Harding
- Dementia and Neurodegenerative Disease Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
| | - Simarjit Kaur Singhrao
- Dementia and Neurodegenerative Disease Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
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Keil J, Rafn GR, Turan IM, Aljohani MA, Sahebjam-Atabaki R, Sun XL. Sialidase Inhibitors with Different Mechanisms. J Med Chem 2022; 65:13574-13593. [PMID: 36252951 PMCID: PMC9620260 DOI: 10.1021/acs.jmedchem.2c01258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 11/28/2022]
Abstract
Sialidases, or neuraminidases, are enzymes that catalyze the hydrolysis of sialic acid (Sia)-containing molecules, mostly removal of the terminal Sia (desialylation). By desialylation, sialidase can modulate the functionality of the target compound and is thus often involved in biological pathways. Inhibition of sialidases with inhibitors is an important approach for understanding sialidase function and the underlying mechanisms and could serve as a therapeutic approach as well. Transition-state analogues, such as anti-influenza drugs oseltamivir and zanamivir, are major sialidase inhibitors. In addition, difluoro-sialic acids were developed as mechanism-based sialidase inhibitors. Further, fluorinated quinone methide-based suicide substrates were reported. Sialidase product analogue inhibitors were also explored. Finally, natural products have shown competitive inhibiton against viral, bacterial, and human sialidases. This Perspective describes sialidase inhibitors with different mechanisms and their activities and future potential, which include transition-state analogue inhibitors, mechanism-based inhibitors, suicide substrate inhibitors, product analogue inhibitors, and natural product inhibitors.
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Affiliation(s)
- Joseph
M. Keil
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Garrett R. Rafn
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Isaac M. Turan
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Majdi A. Aljohani
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Reza Sahebjam-Atabaki
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
| | - Xue-Long Sun
- Department of Chemistry, Chemical and
Biomedical Engineering and Center for Gene Regulation in Health and
Disease (GRHD), Cleveland State University, Cleveland, Ohio 44115, United States
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Kurniyati K, Chang Y, Liu J, Li C. Transcriptional and functional characterizations of multiple flagellin genes in spirochetes. Mol Microbiol 2022; 118:175-190. [PMID: 35776658 PMCID: PMC9481697 DOI: 10.1111/mmi.14959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/28/2022] [Accepted: 06/28/2022] [Indexed: 11/28/2022]
Abstract
The flagellar filament is a helical propeller for bacterial locomotion. In external flagellates, the filaments are mostly homopolymers of a single flagellin protein. By contrast, the flagellar filaments of spirochetes are mostly heteropolymers of multiple flagellin proteins. This report seeks to investigate the role of multiple flagellin proteins using the oral spirochete Treponema denticola as a model. First, biochemical and genetic studies uncover that the flagellar filaments of T. denticola mainly comprise four proteins, FlaA, FlaB1, FlaB2, and FlaB3, in a defined stoichiometry. Second, transcriptional analyses reveal that the genes encoding these four proteins are regulated by two different transcriptional factors, sigma28 and sigma70 . Third, loss-of-function studies demonstrate that each individual flagellin protein contributes to spirochete motility, but none of them is absolutely required. Last, we provide genetic and structural evidence that FlaA forms a "seam"-like structure around the core and that deletion of individual flagellin protein alters the flagellar homeostasis. Collectively, these results demonstrate that T. denticola has evolved a unique mechanism to finely regulate its flagellar filament gene expression and assembly which renders the organelle with the right number, shape, strength, and structure for its distinct motility.
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Affiliation(s)
- Kurni Kurniyati
- Department of Oral Craniofacial Molecular Biology, School of DentistryVirginia Commonwealth UniversityRichmondVirginiaUSA
| | - Yunjie Chang
- Microbial Sciences InstituteYale UniversityWest HavenConnecticutUSA
- Department of Microbial PathogenesisYale School of MedicineNew HavenConnecticutUSA
| | - Jun Liu
- Microbial Sciences InstituteYale UniversityWest HavenConnecticutUSA
- Department of Microbial PathogenesisYale School of MedicineNew HavenConnecticutUSA
| | - Chunhao Li
- Department of Oral Craniofacial Molecular Biology, School of DentistryVirginia Commonwealth UniversityRichmondVirginiaUSA
- Department of Microbiology and Immunology, School of MedicineVirginia Commonwealth UniversityRichmondVirginiaUSA
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Structural and functional characterisation of a stable, broad-specificity multimeric sialidase from the oral pathogen Tannerella forsythia. Biochem J 2022; 479:1785-1806. [PMID: 35916484 PMCID: PMC9472817 DOI: 10.1042/bcj20220244] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022]
Abstract
Sialidases are glycosyl hydrolase enzymes targeting the glycosidic bond between terminal sialic acids and underlying sugars. The NanH sialidase of Tannerella forsythia, one of the bacteria associated with severe periodontal disease plays a role in virulence. Here we show that this broad-specificity enzyme (but higher affinity for α2,3 over α2,6 linked sialic acids) digests complex glycans but not those containing Neu5,9Ac. Furthermore we show it to be a highly stable dimeric enzyme and present a thorough structural analysis of the native enzyme in its apo-form and in complex with a sialic acid analogue/ inhibitor (Oseltamivir). We also use non-catalytic (D237A) variant to characterise molecular interactions while in complex with the natural substrates 3- and 6-siallylactose. This dataset also reveals the NanH Carbohydrate Binding Module (CBM, CAZy CBM 93) has a novel fold made of antiparallel beta-strands. The catalytic domain structure contains novel features that include a non-prolyl cis-peptide and an uncommon arginine sidechain rotamer (R306) proximal to the active site. Via a mutagenesis programme, we identified key active site residues (D237, R212 and Y518) and probed the effects of mutation of residues in proximity to the glycosidic linkage within 2,3 and 2,6-linked substrates. These data revealed that mutagenesis of R306 and residues S235 & V236 adjacent to the acid-base catalyst D237 influence the linkage specificity preference of this bacterial sialidase, opening up possibilities for enzyme engineering for glycotechology applications and providing key structural information that for in silico design of specific inhibitors of this enzyme for treatment of periodontitis.
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Afolayan AO, Biagi E, Rampelli S, Candela M, Brigidi P, Turroni S, Ayeni FA. The Gut Microbiota of an Individual Varies With Intercontinental Four-Month Stay Between Italy and Nigeria: A Pilot Study. Front Cell Infect Microbiol 2021; 11:725769. [PMID: 34881191 PMCID: PMC8646098 DOI: 10.3389/fcimb.2021.725769] [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: 06/15/2021] [Accepted: 11/03/2021] [Indexed: 11/13/2022] Open
Abstract
Despite well-established knowledge of the role of diet and the geographic effect on the gut microbiota of human populations, the temporal dynamics of the individual microbiota profile across changes associated with intercontinental short residence are still far from being understood. This pilot study sought to provide insights into the trajectory of the gut microbiota of an individual during a two-month stay in Italy and a subsequent two-month stay in Nigeria, by 16S rRNA gene sequencing and inferred metagenomics. The gut microbiota underwent massive but temporary changes, both taxonomically and based on predicted functionality. The faecal microbiota associated with the short stay in Italy progressively lost diversity and showed a dominance of Firmicutes, while after returning to Nigeria, the microbial community quickly regained the typical profile, in terms of biodiversity and bacterial signatures of traditional lifestyle, i.e., Prevotella and Treponema. Predicted pathways involved in glycolysis, fermentation and N-acetylneuraminate degradation were enriched during the subsequent two-month stay in Nigeria, whereas pathways associated with amino acid and peptidoglycan synthesis and maturation became over-represented during short stay in Italy. Our findings stress the plasticity of the individual gut microbiota even during a short-term travel, with loss/gain of taxonomic and functional features that mirror those of the gut microbiota of indigenous people dwelling therein.
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Affiliation(s)
- Ayorinde O Afolayan
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Elena Biagi
- Unit of Microbiome Science and Biotechnology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Simone Rampelli
- Unit of Microbiome Science and Biotechnology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Marco Candela
- Unit of Microbiome Science and Biotechnology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Patrizia Brigidi
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Silvia Turroni
- Unit of Microbiome Science and Biotechnology, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Funmilola A Ayeni
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria.,Department of Biology, Simmons University, Boston, MA, United States
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11
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Kim Y, Ko JY, Yang WH. Remodeling of host glycoproteins during bacterial infection. BMB Rep 2021. [PMID: 34674797 PMCID: PMC8633524 DOI: 10.5483/bmbrep.2021.54.11.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Protein glycosylation is a common post-translational modification found in all living organisms. This modification in bacterial pathogens plays a pivotal role in their infectious processes including pathogenicity, immune evasion, and host-pathogen interactions. Importantly, many key proteins of host immune systems are also glycosylated and bacterial pathogens can notably modulate glycosylation of these host proteins to facilitate pathogenesis through the induction of abnormal host protein activity and abundance. In recent years, interest in studying the regulation of host protein glycosylation caused by bacterial pathogens is increasing to fully understand bacterial pathogenesis. In this review, we focus on how bacterial pathogens regulate remodeling of host glycoproteins during infections to promote the pathogenesis.
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Affiliation(s)
- Yeolhoe Kim
- Department of Systems Biology, BK21 Plus Project, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
- Glycosylation Network Research Center, Yonsei University, Seoul 03722, Korea
| | - Jeong Yeon Ko
- Department of Systems Biology, BK21 Plus Project, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
- Glycosylation Network Research Center, Yonsei University, Seoul 03722, Korea
| | - Won Ho Yang
- Department of Systems Biology, BK21 Plus Project, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
- Glycosylation Network Research Center, Yonsei University, Seoul 03722, Korea
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12
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Complete Genome Sequences of Three Human Oral Treponema parvum Isolates. Microbiol Resour Announc 2021; 10:e0039421. [PMID: 34236225 PMCID: PMC8265222 DOI: 10.1128/mra.00394-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Treponema parvum is a spirochete associated with human and animal oral/nonoral soft tissue infections. Here, we report the complete genome sequences of three human oral isolates of T. parvum, namely, ATCC 700770T (OMZ 833T), ATCC 700773 (OMZ 842), and OMZ 843, which possess circular chromosomes of a median size of 2.63 Mb.
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13
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Severi E, Rudden M, Bell A, Palmer T, Juge N, Thomas GH. Multiple evolutionary origins reflect the importance of sialic acid transporters in the colonization potential of bacterial pathogens and commensals. Microb Genom 2021; 7. [PMID: 34184979 PMCID: PMC8461474 DOI: 10.1099/mgen.0.000614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Located at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host-microbe interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These bacteria rely on specific transporters for the acquisition of host-derived sialic acids. Here, we present the first comprehensive genomic and phylogenetic analysis of bacterial sialic acid transporters, leading to the identification of multiple new families and subfamilies. Our phylogenetic analysis suggests that sialic acid-specific transport has evolved independently at least eight times during the evolution of bacteria, from within four of the major families/superfamilies of bacterial transporters, and we propose a robust classification scheme to bring together a myriad of different nomenclatures that exist to date. The new transporters discovered occur in diverse bacteria, including Spirochaetes, Bacteroidetes, Planctomycetes and Verrucomicrobia, many of which are species that have not been previously recognized to have sialometabolic capacities. Two subfamilies of transporters stand out in being fused to the sialic acid mutarotase enzyme, NanM, and these transporter fusions are enriched in bacteria present in gut microbial communities. Our analysis supports the increasing experimental evidence that competition for host-derived sialic acid is a key phenotype for successful colonization of complex mucosal microbiomes, such that a strong evolutionary selection has occurred for the emergence of sialic acid specificity within existing transporter architectures.
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Affiliation(s)
- Emmanuele Severi
- Department of Biology, University of York, York, UK.,Microbes in Health and Disease, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - Andrew Bell
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Tracy Palmer
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Nathalie Juge
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
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14
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Glycan cross-feeding supports mutualism between Fusobacterium and the vaginal microbiota. PLoS Biol 2020; 18:e3000788. [PMID: 32841232 PMCID: PMC7447053 DOI: 10.1371/journal.pbio.3000788] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/10/2020] [Indexed: 12/14/2022] Open
Abstract
Women with bacterial vaginosis (BV), an imbalance of the vaginal microbiome, are more likely to be colonized by potential pathogens such as Fusobacterium nucleatum, a bacterium linked with intrauterine infection and preterm birth. However, the conditions and mechanisms supporting pathogen colonization during vaginal dysbiosis remain obscure. We demonstrate that sialidase activity, a diagnostic feature of BV, promoted F. nucleatum foraging and growth on mammalian sialoglycans, a nutrient resource that was otherwise inaccessible because of the lack of endogenous F. nucleatum sialidase. In mice with sialidase-producing vaginal microbiotas, mutant F. nucleatum unable to consume sialic acids was impaired in vaginal colonization. These experiments in mice also led to the discovery that F. nucleatum may also “give back” to the community by reinforcing sialidase activity, a biochemical feature of human dysbiosis. Using human vaginal bacterial communities, we show that F. nucleatum supported robust outgrowth of Gardnerella vaginalis, a major sialidase producer and one of the most abundant organisms in BV. These results illustrate that mutually beneficial relationships between vaginal bacteria support pathogen colonization and may help maintain features of dysbiosis. These findings challenge the simplistic dogma that the mere absence of “healthy” lactobacilli is the sole mechanism that creates a permissive environment for pathogens during vaginal dysbiosis. Given the ubiquity of F. nucleatum in the human mouth, these studies also suggest a possible mechanism underlying links between vaginal dysbiosis and oral sex. Bacterial mutualism involving the prominent oral bacterium Fusobacterium nucleatum may drive vaginal dysbiosis in women and could help to explain the clinical correlations between vaginal dysbiosis and oral sex.
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15
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Yu S, Fan X, Zheng S, Lin L, Liu J, Pan Y, Li C. The sialidase inhibitor, DANA, reduces Porphyromonas gingivalis pathogenicity and exerts anti-inflammatory effects: An in vitro and in vivo experiment. J Periodontol 2020; 92:286-297. [PMID: 32609876 DOI: 10.1002/jper.19-0688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 04/03/2020] [Accepted: 04/16/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Sialidase has an important role in the pathogenesis of periodontitis and Porphyromonas gingivalis is a sialidase-producing organism implicated in periodontitis development. The aim of this study was to evaluate the anti-virulence and anti-inflammatory properties of the sialidase inhibitor, 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA), in vitro and in vivo. METHODS The effects of DANA on P. gingivalis sialidase and cell viability were determined, and the effects of DANA on P. gingivalis virulence were evaluated by assessment of growth curves, cell morphology, biofilm formation, fimbriae gene expression, and gingipains and lipopolysaccharide (LPS) activity. Anti-inflammatory effects of DANA on LPS-induced macrophages were assessed by measurement of tumor necrosis factor-alpha (TNF-α), interleukin (IL-1β), inducible nitric oxide synthase (iNOS) secretions. The effect of DANA on P. gingivalis-induced periodontitis in rats was analyzed by radiography, stereoscopic microscopy, histopathology, and immunohistochemistry. RESULTS Sialidase inhibition rate of 1mM DANA was 72.01%. Compared with untreated controls, treatment with DANA inhibited P. gingivalis growth and biofilm formation, and significantly decreased expression of the fimA, fimR, and fimS genes, as well as gingipains activity. DANA did not influence macrophage viability, but significantly inhibited TNF-α, IL-1β, and iNOS production in LPS-stimulated macrophages. In the periodontitis rat model, DANA prevented alveolar bone absorption and inhibited TNF-α and IL-1β production. CONCLUSION DANA can reduce the growth, the biofilm formation and the virulence of P. gingivalis and exhibits anti-inflammatory effects, as well as effects against rat periodontitis, suggesting that DANA should be considered for development as a new adjunctive treatment for periodontitis.
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Affiliation(s)
- Shiwen Yu
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Xiaomiao Fan
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Shaowen Zheng
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China.,Liaoning Provincial Key Laboratory of Oral Disease, Shenyang, Liaoning, China
| | - Li Lin
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Jingbo Liu
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China.,Liaoning Provincial Key Laboratory of Oral Disease, Shenyang, Liaoning, China
| | - Yaping Pan
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Chen Li
- School and Hospital of Stomatology, China Medical University, Shenyang, Liaoning, China
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16
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Chu L, Wu Y, Xu X, Phillips L, Kolodrubetz D. Glutathione catabolism by Treponema denticola impacts its pathogenic potential. Anaerobe 2020; 62:102170. [PMID: 32044394 PMCID: PMC7153967 DOI: 10.1016/j.anaerobe.2020.102170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 01/14/2020] [Accepted: 02/04/2020] [Indexed: 12/28/2022]
Abstract
Treponema denticola is a spirochete that is etiologic for periodontal diseases. This bacterium is one of two periodontal pathogens that have been shown to have a complete three step enzymatic pathway (GTSP) that catabolizes glutathione to H2S. This pathway may contribute to the tissue pathology seen in periodontitis since diseased periodontal pockets have lower glutathione levels than healthy sites with a concomitant increase in H2S concentration. In order to be able to demonstrate that glutathione catabolism by the GTSP is critical for the pathogenic potential of T. denticola, allelic replacement mutagenesis was used to make a deletion mutant (Δggt) in the gene encoding the first enzyme in the GTSP. The mutant cannot produce H2S from glutathione since it lacks gamma-glutamyltransferase (GGT) activity. The hemolytic and hemoxidation activities of wild type T. denticola plus glutathione are reduced to background levels with the Δggt mutant and the mutant has lost the ability to grow aerobically when incubated with glutathione. The Δggt bacteria with glutathione cause less cell death in human gingival fibroblasts (hGFs) in vitro than do wild type T. denticola and the levels of hGF death correlate with the amounts of H2S produced. Importantly, the mutant spirochetes plus glutathione make significantly smaller lesions than wild type bacteria plus glutathione in a mouse back lesion model that assesses soft tissue destruction, a major symptom of periodontal diseases. Our results are the first to prove that T. denticola thiol-compound catabolism by its gamma-glutamyltransferase can play a significant role in the in the types of host tissue damage seen in periodontitis.
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Affiliation(s)
- Lianrui Chu
- Department of Developmental Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Yimin Wu
- Department of Developmental Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Xiaoping Xu
- Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Linda Phillips
- Department of Microbiology, Immunology and Molecular Genetics, UT Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - David Kolodrubetz
- Department of Microbiology, Immunology and Molecular Genetics, UT Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
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17
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Frey AM, Satur MJ, Phansopa C, Honma K, Urbanowicz PA, Spencer DIR, Pratten J, Bradshaw D, Sharma A, Stafford G. Characterization of Porphyromonas gingivalis sialidase and disruption of its role in host-pathogen interactions. MICROBIOLOGY-SGM 2020; 165:1181-1197. [PMID: 31517596 DOI: 10.1099/mic.0.000851] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Key to onset and progression of periodontitis is a complex relationship between oral bacteria and the host. The organisms most associated with severe periodontitis are the periodontal pathogens of the red complex: Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis. These organisms express sialidases, which cleave sialic acid from host glycoproteins, and contribute to disease through various mechanisms. Here, we expressed and purified recombinant P. gingivalis sialidase SiaPG (PG_0352) and characterized its activity on a number of substrates, including host sialoglycoproteins and highlighting the inability to cleave diacetylated sialic acids - a phenomenon overcome by the NanS sialate-esterase from T. forsythia. Indeed SiaPG required NanS to maximize sialic acid harvesting from heavily O-acetylated substrates such as bovine salivary mucin, hinting at the possibility of interspecies cooperation in sialic acid release from host sources by these members of the oral microbiota. Activity of SiaPG and P. gingivalis was inhibited using the commercially available chemotherapeutic zanamivir, indicating its potential as a virulence inhibitor, which also inhibited sialic acid release from mucin, and was capable of inhibiting biofilm formation of P. gingivalis on oral glycoprotein sources. Zanamivir also inhibited attachment and invasion of oral epithelial cells by P. gingivalis and other periodontal pathogens, both in monospecies but also in multispecies infection experiments, indicating potential to suppress host-pathogen interactions of a mixed microbial community. This study broadens our understanding of the multifarious roles of bacterial sialidases in virulence, and indicates that their inhibition with chemotherapeutics could be a promising strategy for periodontitis therapy.
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Affiliation(s)
- Andrew M Frey
- University of South Florida, Department of Cell Biology, Microbiology, and Molecular Biology, 4202 East Fowler Ave, ISA2015, Tampa, FL 33620, USA.,Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Marianne J Satur
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Chatchawal Phansopa
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Kiyonobu Honma
- Department of Oral Biology, University at Buffalo, Buffalo, NY, USA
| | | | | | - Jonathan Pratten
- Oral Health R&D, GlaxoSmithKline, St. Georges Avenue, Weybridge, KT13 0DE, UK
| | - David Bradshaw
- Oral Health R&D, GlaxoSmithKline, St. Georges Avenue, Weybridge, KT13 0DE, UK
| | - Ashu Sharma
- Department of Oral Biology, University at Buffalo, Buffalo, NY, USA
| | - Graham Stafford
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
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18
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Lipničanová S, Chmelová D, Ondrejovič M, Frecer V, Miertuš S. Diversity of sialidases found in the human body - A review. Int J Biol Macromol 2020; 148:857-868. [PMID: 31945439 DOI: 10.1016/j.ijbiomac.2020.01.123] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 12/31/2022]
Abstract
Sialidases are enzymes essential for numerous organisms including humans. Hydrolytic sialidases (EC 3.2.1.18), trans-sialidases and anhydrosialidases (intramolecular trans-sialidases, EC 4.2.2.15) are glycoside hydrolase enzymes that cleave the glycosidic linkage and release sialic acid residues from sialyl substrates. The paper summarizes diverse sialidases present in the human body and their potential impact on development of antiviral compounds - inhibitors of viral neuraminidases. It includes a brief overview of catalytic mechanisms of action of sialidases and describes the origin of sialidases in the human body. This is followed by description of the structure and function of sialidase families with a special focus on the GH33 and GH34 families. Various effects of sialidases on human body are also briefly described. Modulation of sialidase activity may be considered a useful tool for effective treatment of various diseases. In some cases, it is desired to completely suppress the activity of sialidases by suitable inhibitors. Specific sialidase inhibitors are useful for the treatment of influenza, epilepsy, Alzheimer's disease, diabetes, different types of cancer, or heart defects. Challenges and future directions are shortly depicted in the final part of the paper.
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Affiliation(s)
- Sabina Lipničanová
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia
| | - Daniela Chmelová
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Miroslav Ondrejovič
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Vladimír Frecer
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-83232 Bratislava, Slovakia; ICARST n.o., Jamnického 19, SK-84101, Bratislava, Slovakia.
| | - Stanislav Miertuš
- Department of Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia; ICARST n.o., Jamnického 19, SK-84101, Bratislava, Slovakia.
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19
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Frey AM, Ansbro K, Kamble NS, Pham TK, Stafford GP. Characterisation and pure culture of putative health-associated oral bacterium BU063 (Tannerella sp. HOT-286) reveals presence of a potentially novel glycosylated S-layer. FEMS Microbiol Lett 2019; 365:5056158. [PMID: 30052903 DOI: 10.1093/femsle/fny180] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/17/2018] [Indexed: 12/19/2022] Open
Abstract
Tannerella HOT-286 (phylotype BU063) is a recently identified novel filamentous Gram-negative anaerobic oral bacterium cultured for the first time recently in co-culture with Propionibacterium acnes. In contrast to the related periodontal disease-associated pathobiont Tannerella forsythia, it is considered a putative health-associated bacterium. In this paper, we identified that this organism could be grown in pure culture if N-acetyl muramic acid (NAM) was provided in the media, although surprisingly the genetic basis of this phenomenon is not likely to be due to a lack of NAM synthesis genes. During further microbiological investigations, we showed for the first time that T. HOT-286 possesses a prominent extracellular S-layer with a novel morphology putatively made up of two proteins modified with an unknown glycan. These data further our knowledge of this poorly understood organism and genus that is an important part of the oral and human microbiome.
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Affiliation(s)
- A M Frey
- School of Clinical Dentistry, University of Sheffield, 19 Claremont Crescent, Sheffield, S10 2TA, UK
| | - K Ansbro
- School of Clinical Dentistry, University of Sheffield, 19 Claremont Crescent, Sheffield, S10 2TA, UK
| | - N S Kamble
- School of Clinical Dentistry, University of Sheffield, 19 Claremont Crescent, Sheffield, S10 2TA, UK
| | - T K Pham
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - G P Stafford
- School of Clinical Dentistry, University of Sheffield, 19 Claremont Crescent, Sheffield, S10 2TA, UK
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20
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In silico analysis as a strategy to identify candidate epitopes with human IgG reactivity to study Porphyromonas gingivalis virulence factors. AMB Express 2019; 9:35. [PMID: 30859419 PMCID: PMC6411804 DOI: 10.1186/s13568-019-0757-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/20/2019] [Indexed: 12/24/2022] Open
Abstract
Porphyromonas gingivalis (Pg) is one of the main pathogens in chronic periodontitis (CP). Studies on the immunogenicity of its virulence factors may contribute to understanding the host response to infection. The present study aimed to use in silico analysis as a tool to identify epitopes from Lys-gingipain (Kgp) and neuraminidase virulence factors of the Pg ATCC 33277 strain. Protein sequences were obtained from the NCBI Protein Database and they were scanned for amino acid patterns indicative of MHC II binding using the MHC-II Binding Predictions tool from the Immune Epitope Database (IEDB). Peptides from different regions of the proteins were chemically synthesized and tested by the indirect ELISA method to verify IgG immunoreactivity in serum of subjects with CP and without periodontitis (WP). T cell epitope prediction resulted in 16 peptide sequences from Kgp and 18 peptide sequences from neuraminidase. All tested Kgp peptides exhibited IgG immunoreactivity whereas tested neuraminidase peptides presented low IgG immunoreactivity. Thus, the IgG reactivity to Kgp protein could be reaffirmed and the low IgG reactivity to Pg neuraminidase could be suggested. The novel peptide epitopes from Pg were useful to evaluate its immunoreactivity based on the IgG-mediated host response. In silico analysis was useful for preselecting epitopes for immune response studies in CP.
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21
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Kurniyati K, Liu J, Zhang JR, Min Y, Li C. A pleiotropic role of FlaG in regulating the cell morphogenesis and flagellar homeostasis at the cell poles of Treponema denticola. Cell Microbiol 2018; 21:e12886. [PMID: 29935042 DOI: 10.1111/cmi.12886] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/23/2018] [Accepted: 06/18/2018] [Indexed: 12/27/2022]
Abstract
FlaG homologue has been found in several bacteria including spirochetes; however, its function is poorly characterised. In this report, we investigated the role of TDE1473, a putative FlaG, in the spirochete Treponema denticola, a keystone pathogen of periodontitis. TDE1473 resides in a large gene operon that is controlled by a σ70 -like promoter and encodes a putative FlaG protein of 123 amino acids. TDE1473 can be detected in the periplasmic flagella (PFs) of T. denticola, suggesting that it is a flagella-associated protein. Consistently, in vitro studies demonstrate that the recombinant TDE1473 interacts with the PFs in a dose-dependent manner and that such an interaction requires FlaA, a flagellar filament sheath protein. Deletion of TDE1473 leads to long and less motile mutant cells. Cryo-electron tomography analysis reveal that the wild-type cells have 2-3 PFs with nearly homogenous lengths (ranging from 3 to 6 μm), whereas the mutant cells have less intact PFs with disparate lengths (ranging from 0.1 to 9 μm). The phenotype of T. denticola TDE1473 mutant reported here is different from its counterparts in other bacteria, which provides insight into further understanding the role of FlaG in the regulation of bacterial cell morphogenesis and flagellation.
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Affiliation(s)
- Kurni Kurniyati
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jun Liu
- Department of Microbial Pathogenesis & Microbial Sciences Institute, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Yunjiang Min
- School of Biological and Pharmaceutical Engineering, West Anhui University, Lu'an, China
| | - Chunhao Li
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, USA
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22
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Evidence for a carbohydrate-binding module (CBM) of Tannerella forsythia NanH sialidase, key to interactions at the host–pathogen interface. Biochem J 2018; 475:1159-1176. [DOI: 10.1042/bcj20170592] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 12/15/2022]
Abstract
Bacterial sialidases cleave terminal sialic acid from a variety of host glycoproteins, and contribute to survival and growth of many human-dwelling bacterial species, including various pathogens. Tannerella forsythia, an oral, Gram-negative, fastidious anaerobe, is a key organism in periodontal disease and possesses a dedicated sialic acid utilisation and scavenging (nan) operon, including NanH sialidase. Here, we describe biochemical characterisation of recombinant NanH, including its action on host-relevant sialoglycans such as sialyl Lewis A and sialyl Lewis X (SLeA/X), and on human cell-attached sialic acids directly, uncovering that it is a highly active broad specificity sialidase. Furthermore, the N-terminal domain of NanH was hypothesised and proved to be capable of binding to a range of sialoglycans and non-sialylated derivatives with Kd in the micromolar range, as determined by steady-state tryptophan fluorescence spectroscopy, but it has no catalytic activity in isolation from the active site. We consider this domain to represent the founding member of a novel subfamily of carbohydrate-binding module (CBM), involved in glycosidase-ligand binding. In addition, we created a catalytically inactive version of the NanH enzyme (FRIP → YMAP) that retained its ability to bind sialic acid-containing ligands and revealed for the first time that binding activity of a CBM is enhanced by association with the catalytic domain. Finally, we investigated the importance of Lewis-type sialoglycans on T. forsythia–host interactions, showing that nanomolar amounts of SLeA/X were capable of reducing invasion of oral epithelial cells by T. forsythia, suggesting that these are key ligands for bacterial–cellular interactions during periodontal disease.
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23
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Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders? J Immunol Res 2018. [PMID: 29507865 DOI: 10.1155/2018/8917804]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Macrophages are key cellular components of the innate immunity, acting as the main player in the first-line defence against the pathogens and modulating homeostatic and inflammatory responses. Plasticity is a major feature of macrophages resulting in extreme heterogeneity both in normal and in pathological conditions. Macrophages are not homogenous, and they are generally categorized into two broad but distinct subsets as either classically activated (M1) or alternatively activated (M2). However, macrophages represent a continuum of highly plastic effector cells, resembling a spectrum of diverse phenotype states. Induction of specific macrophage functions is closely related to the surrounding environment that acts as a relevant orchestrator of macrophage functions. This phenomenon, termed polarization, results from cell/cell, cell/molecule interaction, governing macrophage functionality within the hosting tissues. Here, we summarized relevant cellular and molecular mechanisms driving macrophage polarization in "distant" pathological conditions, such as cancer, type 2 diabetes, atherosclerosis, and periodontitis that share macrophage-driven inflammation as a key feature, playing their dual role as killers (M1-like) and/or builders (M2-like). We also dissect the physio/pathological consequences related to macrophage polarization within selected chronic inflammatory diseases, placing polarized macrophages as a relevant hallmark, putative biomarkers, and possible target for prevention/therapy.
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24
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Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders? J Immunol Res 2018; 2018:8917804. [PMID: 29507865 PMCID: PMC5821995 DOI: 10.1155/2018/8917804] [Citation(s) in RCA: 278] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 11/01/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022] Open
Abstract
Macrophages are key cellular components of the innate immunity, acting as the main player in the first-line defence against the pathogens and modulating homeostatic and inflammatory responses. Plasticity is a major feature of macrophages resulting in extreme heterogeneity both in normal and in pathological conditions. Macrophages are not homogenous, and they are generally categorized into two broad but distinct subsets as either classically activated (M1) or alternatively activated (M2). However, macrophages represent a continuum of highly plastic effector cells, resembling a spectrum of diverse phenotype states. Induction of specific macrophage functions is closely related to the surrounding environment that acts as a relevant orchestrator of macrophage functions. This phenomenon, termed polarization, results from cell/cell, cell/molecule interaction, governing macrophage functionality within the hosting tissues. Here, we summarized relevant cellular and molecular mechanisms driving macrophage polarization in “distant” pathological conditions, such as cancer, type 2 diabetes, atherosclerosis, and periodontitis that share macrophage-driven inflammation as a key feature, playing their dual role as killers (M1-like) and/or builders (M2-like). We also dissect the physio/pathological consequences related to macrophage polarization within selected chronic inflammatory diseases, placing polarized macrophages as a relevant hallmark, putative biomarkers, and possible target for prevention/therapy.
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25
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Li C, Yang X, Pan Y, Yu N, Xu X, Tong T, Tang X, Zhang D, Liu J, Lin L. A Sialidase-DeficientPorphyromonas gingivalisMutant Strain Induces Less Interleukin-1β and Tumor Necrosis Factor-α in Epi4 Cells Than W83 Strain Through Regulation of c-Jun N-Terminal Kinase Pathway. J Periodontol 2017; 88:e129-e139. [DOI: 10.1902/jop.2017.160815] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Chen Li
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Xue Yang
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Yaping Pan
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Ning Yu
- Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, MI
| | - Xiaoyu Xu
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Tong Tong
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Xiaolin Tang
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Dongmei Zhang
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Jingbo Liu
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Li Lin
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
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Kurniyati K, Kelly JF, Vinogradov E, Robotham A, Tu Y, Wang J, Liu J, Logan SM, Li C. A novel glycan modifies the flagellar filament proteins of the oral bacterium Treponema denticola. Mol Microbiol 2017; 103:67-85. [PMID: 27696564 PMCID: PMC5182079 DOI: 10.1111/mmi.13544] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2016] [Indexed: 01/12/2023]
Abstract
While protein glycosylation has been reported in several spirochetes including the syphilis bacterium Treponema pallidum and Lyme disease pathogen Borrelia burgdorferi, the pertinent glycan structures and their roles remain uncharacterized. Herein, a novel glycan with an unusual chemical composition and structure in the oral spirochete Treponema denticola, a keystone pathogen of periodontitis was reported. The identified glycan of mass 450.2 Da is composed of a monoacetylated nonulosonic acid (Non) with a novel extended N7 acyl modification, a 2-methoxy-4,5,6-trihydroxy-hexanoyl residue in which the Non has a pseudaminic acid configuration (L-glycero-L-manno) and is β-linked to serine or threonine residues. This novel glycan modifies the flagellin proteins (FlaBs) of T. denticola by O-linkage at multiple sites near the D1 domain, a highly conserved region of bacterial flagellins that interact with Toll-like receptor 5. Furthermore, mutagenesis studies demonstrate that the glycosylation plays an essential role in the flagellar assembly and motility of T. denticola. To our knowledge, this novel glycan and its unique modification sites have not been reported previously in any bacteria.
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Affiliation(s)
- Kurni Kurniyati
- Department of Oral Biology, The State University of New York at Buffalo, New York 14214, USA
| | - John F. Kelly
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, Canada K1A 0R6
| | - Evgeny Vinogradov
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, Canada K1A 0R6
| | - Anna Robotham
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, Canada K1A 0R6
| | - Youbing Tu
- Department of Oral Biology, The State University of New York at Buffalo, New York 14214, USA
| | - Juyu Wang
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, Texas 77030, USA
| | - Jun Liu
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, Texas 77030, USA
| | - Susan M. Logan
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, Canada K1A 0R6
| | - Chunhao Li
- Department of Oral Biology, The State University of New York at Buffalo, New York 14214, USA
- Department of Microbiology and Immunology, The State University of New York at Buffalo, New York 14214, USA
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Abstract
Sialic acids, or the more broad term nonulosonic acids, comprise a family of nine-carbon keto-sugars ubiquitous on mammalian mucous membranes as terminal modifications of mucin glycoproteins. Sialic acids have a limited distribution among bacteria, and the ability to catabolize sialic acids is mainly confined to pathogenic and commensal species. This ability to utilize sialic acid as a carbon source is correlated with bacterial virulence, especially, in the sialic acid rich environment of the oral cavity, respiratory, intestinal, and urogenital tracts. This chapter discusses the distribution of sialic acid catabolizers among the sequenced bacterial genomes and examines the studies that have linked sialic acid catabolism with increased in vivo fitness in a number of species using several animal models. This chapter presents the most recent findings in sialobiology with a focus on sialic acid catabolism, which demonstrates an important relationship between the catabolism of sialic acid and bacterial pathogenesis.
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pyrF as a Counterselectable Marker for Unmarked Genetic Manipulations in Treponema denticola. Appl Environ Microbiol 2015; 82:1346-52. [PMID: 26682856 DOI: 10.1128/aem.03704-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/14/2015] [Indexed: 12/11/2022] Open
Abstract
The pathophysiology of Treponema denticola, an oral pathogen associated with both periodontal and endodontic infections, is poorly understood due to its fastidious growth and recalcitrance to genetic manipulations. Counterselectable markers are instrumental in constructing clean and unmarked mutations in bacteria. Here, we demonstrate that pyrF, a gene encoding orotidine-5'-monophosphate decarboxylase, can be used as a counterselectable marker in T. denticola to construct marker-free mutants. T. denticola is susceptible to 5-fluoroorotic acid (5-FOA). To establish a pyrF-based counterselectable knockout system in T. denticola, the pyrF gene was deleted. The deletion conferred resistance to 5-FOA in T. denticola. Next, a single-crossover mutant was constructed by reintroducing pyrF along with a gentamicin resistance gene (aacC1) back into the chromosome of the pyrF mutant at the locus of choice. In this study, we chose flgE, a flagellar hook gene that is located within a large polycistronic motility gene operon, as our target gene. The obtained single-crossover mutant (named FlgE(in)) regained the susceptibility to 5-FOA. Finally, FlgE(in) was plated on solid agar containing 5-FOA. Numerous colonies of the 5-FOA-resistant mutant (named FlgE(out)) were obtained and characterized by PCR and Southern blotting analyses. The results showed that the flgE gene was deleted and FlgE(out) was free of selection markers (i.e., pyrF and aacC1). Compared to previously constructed flgE mutants that contain an antibiotic selection marker, the deletion of flgE in FlgE(out) has no polar effect on its downstream gene expression. The system developed here will provide us with a new tool for investigating the genetics and pathogenicity of T. denticola.
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McIntosh E, Bröker M, Wassil J, Welsch J, Borrow R. Serum bactericidal antibody assays – The role of complement in infection and immunity. Vaccine 2015; 33:4414-21. [DOI: 10.1016/j.vaccine.2015.07.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 06/21/2015] [Accepted: 07/07/2015] [Indexed: 11/26/2022]
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Sjögren J, Collin M. Bacterial glycosidases in pathogenesis and glycoengineering. Future Microbiol 2015; 9:1039-51. [PMID: 25340834 DOI: 10.2217/fmb.14.71] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Glycosylation is a common post-translational protein modification and many key proteins of the immune system are glycosylated. As the true experts of our immune system, pathogenic bacteria produce enzymes that can modify the carbohydrates (glycans) of the defense mechanisms in order to favor bacterial survival and persistence. At the intersection between bacterial pathogenesis and glycobiology, there is an increased interest in studying the bacterial enzymes that modify the protein glycosylation of their colonized or infected hosts. This is of great importance in order to fully understand bacterial pathogenesis, but it also presents itself as a valuable source for glycoengineering and glycoanalysis tools. This article highlights the role of bacterial glycosidases during infections, introduces the use of such enzymes as glycoengineering tools and discusses the potential of further studies in this emerging field.
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Affiliation(s)
- Jonathan Sjögren
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, BMC B14, SE-221 84 Lund, Sweden
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31
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Kanamycin Resistance Cassette for Genetic Manipulation of Treponema denticola. Appl Environ Microbiol 2015; 81:4329-38. [PMID: 25888173 DOI: 10.1128/aem.00478-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/14/2015] [Indexed: 12/24/2022] Open
Abstract
Treponema denticola has been recognized as an important oral pathogen of the "red complex" bacterial consortium that is associated with the pathogenesis of endodontal and periodontal diseases. However, little is known about the virulence of T. denticola due to its recalcitrant genetic system. The difficulty in genetically manipulating oral spirochetes is partially due to the lack of antibiotic resistance cassettes that are useful for gene complementation following allelic replacement mutagenesis. In this study, a kanamycin resistance cassette was identified and developed for the genetic manipulation of T. denticola ATCC 35405. Compared to the widely used ermF-ermAM cassette, the kanamycin cassette used in the transformation experiments gave rise to additional antibiotic-resistant T. denticola colonies. The kanamycin cassette is effective for allelic replacement mutagenesis as demonstrated by inactivation of two open reading frames of T. denticola, TDE1430 and TDE0911. In addition, the cassette is also functional in trans-chromosomal complementation. This was determined by functional rescue of a periplasmic flagellum (PF)-deficient mutant that had the flgE gene coding for PF hook protein inactivated. The integration of the full-length flgE gene into the genome of the flgE mutant rescued all of the defects associated with the flgE mutant that included the lack of PF filament and spirochetal motility. Taken together, we demonstrate that the kanamycin resistance gene is a suitable cassette for the genetic manipulation of T. denticola that will facilitate the characterization of virulence factors attributed to this important oral pathogen.
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Abiko Y, Nagano K, Yoshida Y, Yoshimura F. Characterization of Treponema denticola mutants defective in the major antigenic proteins, Msp and TmpC. PLoS One 2014; 9:e113565. [PMID: 25401769 PMCID: PMC4234677 DOI: 10.1371/journal.pone.0113565] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/27/2014] [Indexed: 12/28/2022] Open
Abstract
Treponema denticola, a gram-negative and anaerobic spirochete, is associated with advancing severity of chronic periodontitis. In this study, we confirmed that two major antigenic proteinswere Msp and TmpC, and examined their physiological and pathological roles using gene-deletion mutants. Msp formed a large complex that localized to the outer membrane, while TmpC existed as a monomer and largely localized to the inner membrane. However, TmpC was also detected in the outer membrane fraction, but its cell-surface exposure was not detected. Msp defects increased cell-surface hydrophobicity and secretion of TNF-α from macrophage-like cells, whereas TmpC defects decreased autoagglutination and chymotrypsin-like protease activities. Both mutants adhered to gingival epithelial cells similarly to the wild-type and showed slightly decreased motility. In addition, in Msp-defective mutants, the TDE1072 protein, which is a major membrane protein, was abolished; therefore, phenotypic changes in the mutant can be, at least in part, attributed to the loss of the TDE1072 protein. Thus, the major antigenic proteins, Msp and TmpC, have significant and diverse impacts on the characteristics of T. denticola, especially cell surface properties.
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Affiliation(s)
- Yuki Abiko
- Department of Microbiology, School of Dentistry, Aichi Gakuin University Nagoya, Aichi, Japan
| | - Keiji Nagano
- Department of Microbiology, School of Dentistry, Aichi Gakuin University Nagoya, Aichi, Japan
| | - Yasuo Yoshida
- Department of Microbiology, School of Dentistry, Aichi Gakuin University Nagoya, Aichi, Japan
| | - Fuminobu Yoshimura
- Department of Microbiology, School of Dentistry, Aichi Gakuin University Nagoya, Aichi, Japan
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Abstract
Oral colonising bacteria are highly adapted to the various environmental niches harboured within the mouth, whether that means while contributing to one of the major oral diseases of caries, pulp infections, or gingival/periodontal disease or as part of a commensal lifestyle. Key to these infections is the ability to adhere to surfaces via a range of specialised adhesins targeted at both salivary and epithelial proteins, their glycans and to form biofilm. They must also resist the various physical stressors they are subjected to, including pH and oxidative stress. Possibly most strikingly, they have developed the ability to harvest both nutrient sources provided by the diet and those derived from the host, such as protein and surface glycans. We have attempted to review recent developments that have revealed much about the molecular mechanisms at work in shaping the physiology of oral bacteria and how we might use this information to design and implement new treatment strategies.
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Damgaard C, Holmstrup P, Van Dyke TE, Nielsen CH. The complement system and its role in the pathogenesis of periodontitis: current concepts. J Periodontal Res 2014; 50:283-93. [PMID: 25040158 DOI: 10.1111/jre.12209] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2014] [Indexed: 12/11/2022]
Abstract
Periodontitis is a highly prevalent inflammatory disease in tooth supporting tissues, induced by bacteria growing in a biofilm on tooth surfaces. Components of the complement system are present in the periodontal tissue and the system is activated in periodontitis. Continuous complement activation and modulation by bacteria within the biofilm in periodontal pockets, however, may enhance local tissue destruction, providing the biofilm with both essential nutrients and space to grow. A more profound understanding of the mechanisms involved in complement-derived tissue degradation may facilitate the development of new treatment concepts for periodontitis. Further studies on the role of complement in periodontitis pathogenesis may also contribute to the understanding of why some individuals fail to resolve periodontitis. Here, we review evidence that links complement to the pathogenesis of periodontitis with an emphasis on interaction of complement with bacteria from periodontitis-associated biofilm.
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Affiliation(s)
- C Damgaard
- Section for Periodontology, Microbiology and Community Dentistry, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases and Rheumatology, Institute for Inflammation Research, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, Massachusetts, USA
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35
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Amano A, Chen C, Honma K, Li C, Settem R, Sharma A. Genetic characteristics and pathogenic mechanisms of periodontal pathogens. Adv Dent Res 2014; 26:15-22. [PMID: 24736700 PMCID: PMC6636228 DOI: 10.1177/0022034514526237] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Periodontal disease is caused by a group of bacteria that utilize a variety of strategies and molecular mechanisms to evade or overcome host defenses. Recent research has uncovered new evidence illuminating interesting aspects of the virulence of these bacteria and their genomic variability. This paper summarizes some of the strategies utilized by the major species - Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Porphyromonas gingivalis - implicated in the pathogenesis of periodontal disease. Whole-genome sequencing of 14 diverse A. actinomycetemcomitans strains has revealed variations in their genetic content (ranging between 0.4% and 19.5%) and organization. Strikingly, isolates from human periodontal sites showed no genomic changes during persistent colonization. T. forsythia manipulates the cytokine responses of macrophages and monocytes through its surface glycosylation. Studies have revealed that bacterial surface-expressed O-linked glycans modulate T-cell responses during periodontal inflammation. Periodontal pathogens belonging to the "red complex" consortium express neuraminidases, which enables them to scavenge sialic acid from host glycoconjugates. Analysis of recent data has demonstrated that the cleaved sialic acid acts as an important nutrient for bacterial growth and a molecule for the decoration of bacteria surfaces to help evade the host immune attack. In addition, bacterial entry into host cells is also an important prerequisite for the lifestyle of periodontal pathogens such as P. gingivalis. Studies have shown that, after its entry into the cell, this bacterium uses multiple sorting pathways destined for autophagy, lysosomes, or recycling pathways. In addition, P. gingivalis releases outer membrane vesicles which enter cells via endocytosis and cause cellular functional impairment.
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Affiliation(s)
- A. Amano
- Department of Preventive Dentistry,
Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-Osaka 565-0871,
Japan
| | - C. Chen
- Division of Periodontology, Diagnostic
Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of
Southern California, Los Angeles, CA, USA
| | - K. Honma
- Department of Oral Biology, School of
Dental Medicine, the State University of New York at Buffalo, NY 14214, USA
| | - C. Li
- Department of Oral Biology, School of
Dental Medicine, the State University of New York at Buffalo, NY 14214, USA
- Department of Microbiology and
Immunology, the State University of New York at Buffalo, NY 14214, USA
| | - R.P. Settem
- Department of Oral Biology, School of
Dental Medicine, the State University of New York at Buffalo, NY 14214, USA
| | - A. Sharma
- Department of Oral Biology, School of
Dental Medicine, the State University of New York at Buffalo, NY 14214, USA
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Settem RP, Honma K, Stafford GP, Sharma A. Protein-linked glycans in periodontal bacteria: prevalence and role at the immune interface. Front Microbiol 2013; 4:310. [PMID: 24146665 PMCID: PMC3797959 DOI: 10.3389/fmicb.2013.00310] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 09/27/2013] [Indexed: 12/20/2022] Open
Abstract
Protein modification with complex glycans is increasingly being recognized in many pathogenic and non-pathogenic bacteria, and is now thought to be central to the successful life-style of those species in their respective hosts. This review aims to convey current knowledge on the extent of protein glycosylation in periodontal pathogenic bacteria and its role in the modulation of the host immune responses. The available data show that surface glycans of periodontal bacteria orchestrate dendritic cell cytokine responses to drive T cell immunity in ways that facilitate bacterial persistence in the host and induce periodontal inflammation. In addition, surface glycans may help certain periodontal bacteria protect against serum complement attack or help them escape immune detection through glycomimicry. In this review we will focus mainly on the generalized surface-layer protein glycosylation system of the periodontal pathogen Tannerella forsythia in shaping innate and adaptive host immunity in the context of periodontal disease. In addition, we will also review the current state of knowledge of surface protein glycosylation and its potential for immune modulation in other periodontal pathogens.
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Affiliation(s)
- Rajendra P Settem
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, State University of New York Buffalo, NY, USA
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